Showing papers on "Olfactory system published in 1980"
TL;DR: All of the telencephalic sensory systems of the rhesus monkey are examined for efferents to the amygdala and immediately surrounding structures, using primarily the Fink‐Heimer technique to understand how sensory stimuli influence emotional processes.
Abstract: As part of an attempt to understand how sensory stimuli influence emotional processes we examined all of the telencephalic sensory systems of the rhesus monkey for efferents to the amygdala and immediately surrounding structures, using primarily the Fink-Heimer technique. The results support the following conclusions.
1. All sensory systems contain areas that project to the amygdaloid complex (the somatosensory system, tentatively so), but not to more central limbic structures in the basal forebrain and hypothalamus. Consequently, whatever influence the sensory systems have on emotional processes mediated by these more central limbic structures is likely to depend largely on relays through the amygdala.
2. Except for the olfactory system, the amygdalopetal projections arise only from the later stages of cortical processing within each sensory system, i.e., from the modality-specific association areas one or more steps removed from the primary sensory areas. Thus, the modality-specific cortical sources of the amygdalopetal projections, like their amygdaloid targets, are important links in the sensory-limbic pathways. These sources are: for vision, areas TE and ventral TG; for audition, anterior TA and dorsal TG; for taste, area IA; and for somesthesis, possibly areas IA or IB. The amygdalopetal sources thus occupy a limited territory that begins dorsally in the anterior insula and extends ventrally across the anterior temporal neocortex as far as the rhinal fissure.
3. Within the visual system, progressively heavier and more widespread efferents arise from successively later stages of the amygdalopetal sources. The posterior half of TE sends a moderate projection to the dorsal part of the lateral nucleus, the anterior half of TE sends a heavy projection to the dorsal parts of both the lateral and basal nuclei, and the ventral part of TG sends a heavy projection to the dorsal and medial parts of the lateral and basal nuclei and to the dorsal part of the basal accessory nucleus. This pattern of progressive intensification and spread of the amygdalopetal projections applies also to the auditory system and probably to the other cortical sensory systems as well. The pattern suggests that a progressively greater influence on amygdaloid activity is exerted by successively more highly processed sensory information.
4. The efferents to the amygdaloid complex from the different sensory systems terminate in a dovetailed pattern. The major amygdaloid targets are: for vision, the anterodorsal parts of the lateral, basal, and basal accessory nuclei; for audition, the posterior parts of the lateral and basal accessory nuclei; for taste, the medial parts of the lateral and basal nuclei; and for olfaction, the cortical and medial nuclei. This pattern implies that each part of the amygdala is under the major influence of a particular sensory system.
5. The same cortical areas that give rise to separate sensory channels to the amygdala send efferents that converge upon the perirhinal and prorhinal cortices, areas known to be a major source of input to the hippocampus. Consequently, both the amygdala and hippocampus can be activated by the same highly processed sensory information, a conclusion that may help to account for a recent finding that these two structures can substitute for each other in a mechanism for recognition memory.
521 citations
TL;DR: Observations indicate that axons innervating the piriform cortex do not emit many long collaterals after they leave the lateral olfactory bulb, but there were regions of greater density of labeled that differed in the various brains.
Abstract: The organization of the projection of olfactory bulb output cells was studied in the rat by injection of horseradish peroxidase (HRP) into the piriform cortex or olfactory tubercle. We made single HRP injections into small cuts in the fiber layer of the projection areas in order to enhance uptake by axons and to confine the region of HRP uptake. Following most of these injections, HRP-labeled axons could be traced in discrete fascicles through the fiber layer of the cortex or tubercle. These observations indicate that axons innervating the piriform cortex do not emit many long collaterals after they leave the lateral olfactory tract. HRP-labeled cells were generally observed throughout the ipsilateral olfactory bulb, but there were regions of greater density of labeled cells that differed in the various brains. The differences among the distributions of labeled mitral and tufted cells were analyzed statistically in 39 brains to test whether they varied systematically with injection site. In these analyses, the olfactory bulb was divided into 30 standard regions, and the labeled cells in each regions were counted. The distributions of labeled cells were similar for brains where injections were made into similar regions of the piriform cortex. The variations in density of labeled cells of the dorsal and anterior regions of the olfactory bulb were most strongly correlated with the positions of cortical injections. In contrast, the posterior medial regions of the bulb were heavily labeled after almost all injections. The ventral portions of the olfactory bulb were most heavily labeled after injections into the olfactory tubercle.
253 citations
TL;DR: The olfactory marker protein has been studied in mouse during embryogenesis and in the postnatal period up to 30 days, with the unlabeled antibody enzyme method of immunohistochemistry to correlate its appearance with significant developmental phenomena.
233 citations
TL;DR: Olfactory threshold and detection ability remained unaffected by any of these lesions; however, subjects with MD and RS lesions were markedly impaired on odor discriminations and were more profoundly impaired when the stimuli to be discriminated were novel or difficult to associate.
Abstract: The "core" subnucleus of the mediodorsal thalamic nucleus (MD) receives direct input from olfactory cortex in the rat. This part of MD projects to the frontal neocortex of the rhinal sulcus (RS), while other parts of the MD project to the anterior medial wall of the neocortex (MW). In this study, rats were tested on odor threshold, detection of specific odors, and three odor discriminations both before and after lesions of MD, MW, RS, or sham lesions. Olfactory threshold and detection ability remained unaffected by any of these lesions; however, subjects with MD and RS lesions were markedly impaired on odor discriminations. Furthermore, subjects were more profoundly impaired when the stimuli to be discriminated were novel or difficult to associate. Thus, MD and its "olfactory" projection target, RS, seem to mediate cognitive, rather than sensory aspects of odor-guided behavior in the rat.
183 citations
TL;DR: A retrograde labeling procedure utilizing fluorescent substances was used to establish the presence of branching axons in the ascending raphe system of young rats, and each class of neurons, i.e. single-, double- and triple-labeled, were shown to have a predominant distribution within specific parts of the nucleus.
126 citations
TL;DR: Axotomy of the olfactory sensory neurons in the adult primate squirrel monkey induces retrograde degeneration of the perikarya in the nasal neuroepithelium, which results in loss of mature neurons and replacement of experimentally degenerated neurons.
117 citations
TL;DR: The role of the thalamocortical ''olfactory'' pathway in odor preferences and sexual behavior was examined in the hamster, a species which depends crucially upon olfaction for mating.
Abstract: The role of the thalamocortical "olfactory" pathway in odor preferences and sexual behavior was examined in the hamster, a species which depends crucially upon olfaction for mating Before and after ablation of primary or secondary olfactory structures, male hamsters were tested for threshold, interest, and preference for the odor of an estrus female hamster and other odors Sexual competency was also observed in daily mating sessions Disruption of the primary olfactory pathway resulted in an absence of interest in odors and mating Lesions of the mediodorsal thalamic nucleus or frontal neocortex of the rhinal sulcus did not result in anosmia, but did eliminate or alter odor preferences and resulted in inappropriate, inefficient, precopulatory and copulatory behavior It appears that substructures in the thalamofrontal pathway playa role in discriminative or cognitive aspects of processing adaptively significant stimuli
102 citations
TL;DR: The properties of olfactory mutations on the X-chromosome are described and the behavior of mutants with normal flies are compared and compared to normal flies.
Abstract: The olfactory system of Drosophila is readily amenable to genetic dissection. The response to smell involves interaction between a chemical stimulant and the receptor surface, transduction, neural excitation, transmission across synapses and integration by the central nervous system finally leading to motor activity. By an appropriate choice of mutants, attention can be focussed on any one of this series of complex processes. In this paper I will describe the properties of olfactory mutations on the X-chromosome and compare the behavior of mutants with normal flies.
74 citations
TL;DR: The results emphasize that glutamate and aspartate can evoke a variety of neuronal responses from olfactory cortex neurones that were previously undetected in experiments based on extracellular recordings.
73 citations
TL;DR: The observations indicate that this portion of the CNS of a non-human primate can be reinnervated after deafferentiation, and that active synaptogenesis occurs.
68 citations
TL;DR: The results suggest that penicillin blocks the response mechanism rather than the receptors mediating depolarizations by GABA and muscimol, and this pattern of antagonism was distinctly different from the antagonism exerted by bicuculline, picrotoxin and strychnine.
1 Jan 1980
TL;DR: The vomeronasal organ in the hamster became a source of great interest when Powers and Winans reported in 1975 that vomer onasal nerve damage produced some deficits in male mating behavior but that almost complete destruction of the olfactory epithelium did not.
Abstract: The vomeronasal organ in the hamster became a source of great interest when Powers and Winans reported in 1975 that vomeronasal nerve damage produced some deficits in male mating behavior but that almost complete destruction of the olfactory epithelium did not. At about the same time Singer, O’Connell and coworkers showed that a pure chemical. Dimethyl disulfide (DMDS), could be isolated from hamster vaginal discharge (HVD), and accounted for much of the attractiveness of the discharge. We were therefore interested in studying the electrophysiological responses of the vomeronasal system to components of hamster vaginal discharge and other chemicals. Adrian (1955) and Tucker (1963) had failed to elicit electrical activity in the vomeronasal nerve and accessary olfactory bulb (AOB) of the rabbit when odors were simply blown over the entrance to the vomeronasal duct. This was also our experience with the hamster, presumably because no odor molecules could reach the receptor epithelium sequestered inside the vomeronasal organ. When the odor can reach the receptors, odor responses can be evoked. Figure 1 shows the response of a single unit recorded in the accessory olfactory bulb to odor blown over the surgically exposed vomeronasal epithelium in the hamster. The diagram at the right shows the experimental setup. At the top left is a peristimulus time histogram for four repetitions of amyl acetate stimulation. These data are replotted below as firing rate above or below prestimulus spontaneous rate (zero on ordinate). There is a clear response to amyl acetate which starts within the first second and peaks within the first five seconds.
TL;DR: A comparison of olfactory receptor responses of three species of freshwater catfishes (family Ictaluridae) and one species of marine catfish (family Arridae) was performed, finding that the responses of the freshwater species were similar to those of the marine species.
Abstract: A comparison of olfactory receptor responses of three species of freshwater catfishes (family Ictaluridae) and one species of marine catfish (family Arridae) was performed. With the exception of the reduced response of the sea catfish (Arius felis) to L-glutamine, no distinctive species specific differences in the electro-olfactogram (EOG) responses were noted. The phasic EOG response increased exponentially with a logarithmic increase in amino acid concentration from threshold to 10−2M. The relative stimulatory effectiveness of the amino acids tested was similar among the four species. The olfactory receptors were highly responsive to L-cysteine and to amino acids containing five carbon atoms having unbranched and uncharged side chains. From phyletic relationships of the species tested, the present data suggest that the olfactory system of the North American catfishes has remained temporally conservative.
TL;DR: Evidence from the literature for cholinergic innervation of the mammalian olfactory bulb was assessed in light of possible correlation between reported sites of termination of centrifugal fibers to the o aroma bulb and the localization of AChE.
Abstract: Experiments were conducted to examine by light and electron microscopy the localization of acetylcholinesterase (AChE) in the main (MOB) and accessory (AOB) olfactory bulbs of the normal mouse. Evidence from the literature for cholinergic innervation of the mammalian olfactory bulb was then assessed in light of possible correlation between reported sites of termination of centrifugal fibers to the olfactory bulb and the localization of AChE. AChE-positive nerve fibers were concentrated in the periglomerular region and internal plexiform layer of the MOB. Stained fibers were also present in the granule cell, mitral cell, and external plexiform layers as well as within glomeruli. A few neurons in all layers of the MOB contained AChE reaction product. Unlike the MOB, AChE-positive fibers were not present in the glomerular layer of the AOB. AChE-positive fibers were concentrated in the inner plexiform layer, whereas fewer stained fibers were observed in the external plexiform and mitral cell layer and granule cell layer. Lightly stained neurons were found in the deeper portions of the external plexiform and mitral cell layer and granule cell layer. Ultrastructurally, AChE reaction product in the MOB and AOB was predominantly associated with small unmyelinated axons. Reaction product was also observed adjacent to axon terminals and dendrites. Occasionally within the MOB, AChE activity was found within periglomerular, tufted, short-axon, mitral, and granule cells. In the AOB, however, intracellular AChE activity was observed within some mitral/tufted cells and only a few granule cells. In conclusion, the AChE reaction product was mainly associated with axons in regions of the MOB where centrifugal fibers have been reported. Accessory olfactory bulb AChE localization was different from that of the MOB, suggesting a different pattern of cholinergic input to the AOB. The small amounts and sites of intraneuronal AChE reaction product in cells of the olfactory bulb indicate cholinoceptive rather than cholinergic function.
TL;DR: It is demonstrated that in the mammalian olfactory system there exists a topographical projection of input from localized regions in the epithelium onto the second-order neurons in the Olfactory bulb.
Abstract: Electrical stimulation of nerve fibers emerging from different positions of the olfactory epithelium was used to determine the receptive fields for 52 olfactory bulb neurons in the hamster. The responses of olfactory bulb neurons were recorded extracellularly with metal-filled micropipettes. Suprathreshold stimuli (500 microA) were applied to each of eight standard epithelial positions spaced approximately 250 microns apart, and the position, or positions, which, when stimulated, produced a response in the bulb were taken as an index of the neuron's receptive field. The results indicate that most bulb neurons have very localized receptive fields limited to only one or two stimulating positions. Furthermore, there was a statistically significant correlation between the location of a neuron's receptive field in the olfactory epithelium and the recording depth of the neuron in the olfactory bulb (Spearman rank correlation coefficient, rs, 0.67, P < 0.001). These findings demonstrate that in the mammalian olfactory system there exists a topographical projection of input from localized regions in the epithelium onto the second-order neurons in the olfactory bulb.
TL;DR: Regeneration of the nerve, crushed 1.5 cm from the cell bodies, is found to produce three distinct populations of regenerating fibers, each representing between 50 and 70% of the original axonal population.
Abstract: Previous studies of the olfactory nerve, mainly in higher vertebrates, have indicated that axonal injury causes total degeneration of the mature neurons, followed by replacement of new neuronal cells arising from undifferentiated mucosal cells. A similar regeneration process was confirmed in the garfish olfactory system. Regeneration of the nerve, crushed 1.5 cm from the cell bodies, is found to produce three distinct populations of regenerating fibers. The first traverses the crush site 1 wk postoperative and progresses along the nerve at a rate of 5.8 +/- 0.3 mm/d for the leading fibers of the group. The second group of fibers traverses the crush site after 2 wk postcrush and advances at a rate of 2.1 +/- 0.1 mm/d for the leading fibers. The rate of growth of this group of fibers remains constant for 60 d but subsequently falls to 1.6 +/- 0.2 for the leading population of fibers. The leading fibers in the third group of regenerating axons traverse the crush site after 4 wk and advance at a constant rate of 0.8 +/- 0.2 mm/d. The multiple populations of regenerating fibers with differing rates of growth are discussed in the context of precursor cell maturity at the time of nerve injury and possible conditioning effects of the lesion upon these cells. Electron microscopy indicates that the number of axons decreases extensively after crush. The first two phases of regenerating axons represent a total of between 6 and 10% of the original axonal population and are typically characterized by small fascicles of axons surrounded by Schwann cells and large amounts of collagenous material. The third phase of fibers represents between 50 and 70% of the original axonal population.
TL;DR: The structure and development of the olfactory organ in the garfish Belone belone (L.) were studied by light and electron microscopy (SEM and TEM) andiating dendritic endings were found and are considered an indication of ongoing cell dynamics.
Abstract: Theisen, B., Breucker, H., Zeiske, E., Melinkat, R. 1980. Structure and development of the olfactory organ in the garfish Belone belone (L.) (Teleostei, Atheriniformes). (Institute of Comparative Anatomy, University of Copenhagen, Denmark; Anatomisches Institut, Universitat Hamburg, and Zoologisches Institut und Zoologisches Museum, Universitat Hamburg, Federal Republic of Germany.) — Acta zool. (Stockh.) 61(3): 161–170.
The structure and development of the olfactory organ in the garfish Belone belone (L.) were studied by light and electron microscopy (SEM and TEM). The olfactory organ has the shape of an open groove with a protruding papilla. In embryos and early juveniles the groove is smooth and is provided with a continuous sensory epithelium. During ontogenesis the papilla develops and the composition of the epithelium is changed as areas of nonsensory epithelium appear and eventually separate the sensory epithelium into islets. In adults the sensory epithelium consists of supporting, basal, and two types of receptor cells, ciliated and microvillous. In juveniles also ciliated nonsensory cells are present. This difference can be correlated with differing locomotory habits of adults and juveniles. The receptor cilia show a 9 + 0 microtubular pattern while the nonsensory cilia have the general 9 + 2 pattern. Deviating dendritic endings were found and are considered an indication of ongoing cell dynamics.
TL;DR: An atlas of stereotaxic variability of cerebral structures in the frontal plane of the adult male hooded rat is illustrated by photomicrographs showing myelinated pathways and nuclear structures.
TL;DR: The results indicate that the lateral and intermediate Olfactory pathways are not essential for smell and suggest that significant olfactory function may be mediated by medial olfactometer bulb projections.
TL;DR: The results showed that, contrary to findings in some rodents, prepubertal bilateral bulbectomy in the male pig had no significant effect on mating or aggressive behaviour, or testicular function in so far as complete spermatogenesis was present and normal levels of androgen and pheromone were maintained together with the integrity of the accessory organs as mentioned in this paper.
Abstract: Bilateral olfactory bulb ablation was carried out surgically on 8 prepubertal Large White boars when they were 10-12 weeks of age. Between 26 weeks and slaughter at 47-49 weeks of age, androgen was determined in peripheral blood plasma of bulbectomized and unoperated control animals. The pigs were exposed to oestrous female pigs to observe mating behaviour, and to alien boars to observe aggressive behaviour. Saliva produced during behaviour tests was extracted with diethyl ether and levels of the pheromonal 16-androstene steroids in the extracts were determined by a colorimetric assay. After slaughter the testes, accessory organs and submaxillary glands were weighed, and pices of tissue together with olfactory epithelium were processed for light microscopy; fructose and zinc were determined in the seminal vesicles. The results showed that, contrary to findings in some rodents, prepubertal bilateral bulbectomy in the male pig had no significant effect on mating or aggressive behaviour, or testicular function in so far as complete spermatogenesis was present and normal levels of androgen and pheromone were maintained together with the integrity of the accessory organs. However, in keeping with findings in other species, the height of the olfactory epithelium was generally reduced in the bulbectomized pigs.
TL;DR: The results suggest a competitive reinnervation process and provide a fine structural explanation for the events leading to alterations in this pathway following neonatal deafferentation.
Abstract: The olfactory cortex of rats is being studied at various survival times following deafferentating olfactory bulb ablation on the day of birth. The neonatal axons and synaptic terminals undergo rapid, flocculent degeneration and fragmentation. Most are not electron-dense and therefore probably not argyrophilic at this particular age of the lesion. The degeneration and removal of debris is far more rapid than in adults, yielding a markedly enlarged extracellular space with a relative absence of glia at the vacated postsynaptic "thickenings". Denervated postsynaptic "thickenings" become occupied by neuronal and nonneuronal profiles and profiles of uncertain origin, singly or in various combinations, or the sites may remain partially vacant. One or more axons with synaptic vesicles often aggregated at the site are commonly involved. Certain terminals form contacts on progressively greater lengths of the "thickening" until typical synaptic contacts predominate by 14 days survival. The results suggest a competitive reinnervation process and provide a fine structural explanation for the events leading to alterations in this pathway following neonatal deafferentation.
TL;DR: The results suggest: 1) Glutamate and aspartate are specifically associated with mitral (and presumably also tufted) cell axons and terminals in the piriform cortex, and 2) Glycine is unlikely to play a prominent neurotransmitter role in either the olfactory bulb or Olfactory cortex.
Abstract: Levels of the proposed neurotransmitter amino acids glutamate, aspartate, gamma-aminobutyric acid (GABA), and glycine were measured within the layered structures of the olfactory bulb and olfactory cortex following unilateral transections of the lateral olfactory tract or of virtually all fiber tracts of the olfactory peduncle. Distributions of the amino acids on both lesion and control sides were examined and compared by means of a mapping procedure. The results suggest: 1) Glutamate and aspartate are specifically associated with mitral (and presumably also tufted) cell axons and terminals in the piriform cortex. The distribution of aspartate in the olfactory bulb is further suggestive of a specific association of aspartate with mitral cell dendrites and somata. 2) Glutamate might be specifically associated with some centrifugal fibers traveling to the olfactory bulb in or near the anterior commissure. 3) GABA might be specifically related to some certrifugal fibers to the olfactory bulb in addition to its prominent association with granule cells of the bulb. 4) Glycine is unlikely to play a prominent neurotransmitter role in either the olfactory bulb or olfactory cortex.
01 Mar 1980-Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology
TL;DR: The previously reported results of degeneration following unilateral olfactory bulb lesions were confirmed by these physiological data, and basic agreement was also observed between the physiological characteristics of the pigeon's Olfactory pathway and those reported for mammals.
Abstract: This work is part of an extensive study of anatomical, physiological, and behavioral characteristics of the olfactory system of birds. The present report deals primarily with the evoked potentials recorded from the olfactory bulb and several forebrain sites following electrical stimulation of one olfactory nerve. Our previously reported results of degeneration following unilateral olfactory bulb lesions were confirmed by these physiological data, and basic agreement was also observed between the physiological characteristics of the pigeon's olfactory pathway and those reported for mammals. Nerve conduction velocity is 0.2–0.4 m/s. Response latency in the olfactory bulb is 20–40 ms ipsilaterally and 2–5 ms longer contralaterally, with amplitudes to 4 mV and polarity reversal across the mitral-granular cell region. Responses in sites that show degeneration after bulbar lesions (ipsilateral cortex prepyriformis, lobus parolfactorius, and ventral hyperstriatum; contralateral paleostriatum) are biphasic, 2–5 ms slower than those in the bulb, and fail to follow repetitive stimulation. Those in other ipsilateral forebrain regions showing no degeneration (paleostriatum, caudal neostriatum, and anterior hyperstriatum) are polyphasic, are much slower than those in the bulb, and have smaller amplitudes. Unit activity in all of these sites was modified by olfactory nerve stimulation. Poststimulus time histograms of unit activity show firing patterns that were correlated with amplitude variations in simultaneously recorded evoked potentials.
TL;DR: The decrease in rat olfactory bulb NE levels may be involved in castration-induced changes in preferences for conspecific odors.
TL;DR: The results emphasize the dependence on an intact olfactory system of several courtship or agonistic behaviors that affect hamster reproduction by functioning as noncontact communications and suggest differences in the brain and sensory mechanisms that control distinct types of reproductive behavior.
TL;DR: Results support the presence of LC fibers which influence OT neurons, which were seen in the LC after HRP application to the OT in rats and cats.
TL;DR: It is suggested that the observed retardations in body and brain growth resemble those experienced by animals undernourished during the early postnatal period, indicating that the anosmic pups by virtue of the loss of needed olfactory cues are undermourished.
TL;DR: It is possible that bulbectomy may enhance behavioral sensitivity to EB by disrupting biochemical responses to EB in limbic system structures which normally exert an inhibitory influence over sexual receptivity.
TL;DR: A fatal case of herpes simplex encephalitis contained viruses within the olfactory pathway but not in the trigeminal ganglia, and this finding supports the theory that the Olfactory nerves are the portal of entry in adult herpessimplexEncephalitis.
TL;DR: Olfactory function was found to be diminished in elderly subjects and should be considered a factor when evaluating older patients.
Abstract: An objective examination of olfactory function is needed for evaluation and clinical progression of patients with olfactory deficits. Two hundred sixty-eight healthy subjects were studied in order to establish olfactory thresholds for three test odorants. Subjects were required to simply detect the presence of an odor when comparing various log dilutions of test odorant against two “blank” flasks. These data have provided a means of quantitating existing olfactory deficits in affected patients. Olfactory function was found to be diminished in elderly subjects and should be considered a factor when evaluating older patients.