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The role of the olfactory tubercle in the effects of cocaine, morphine and brain-stimulation reward.Brain Research Feb 1991Using the quantitative 2-[14C]deoxyglucose autoradiographic method, local rates of glucose utilization were measured in rats after the administration of morphine or...
Using the quantitative 2-[14C]deoxyglucose autoradiographic method, local rates of glucose utilization were measured in rats after the administration of morphine or cocaine in the presence or absence of rewarding brain stimulation to the medial forebrain bundle. In animals that did not receive brain stimulation, cocaine significantly increased glucose utilization in the olfactory tubercle, medial prefrontal cortex and substantia nigra pars reticulata, whereas morphine significantly increased glucose metabolism in the olfactory tubercle only. Stimulation itself increased metabolic rates in a number of sites, such as the olfactory tubercle, nucleus accumbens, medial prefrontal cortex, ventral tegmental area and others. However, in self-stimulating animals both morphine and cocaine caused further increases in activity in the olfactory tubercle. Since the olfactory tubercle was the only structure to cause a significant increase in metabolic rate following each treatment, the results implicate this limbic structure in the rewarding effects of morphine, cocaine and brain-stimulation reward.
Topics: Animals; Brain; Cocaine; Electric Stimulation; Glucose; Male; Morphine; Olfactory Bulb; Rats; Rats, Inbred F344; Reward; Sodium Chloride; Tissue Distribution
PubMed: 2029627
DOI: 10.1016/0006-8993(91)91076-d -
ELife Dec 2017Odor-preferences are usually influenced by life experiences. However, the neural circuit mechanisms remain unclear. The medial olfactory tubercle (mOT) is involved in...
Odor-preferences are usually influenced by life experiences. However, the neural circuit mechanisms remain unclear. The medial olfactory tubercle (mOT) is involved in both reward and olfaction, whereas the ventral tegmental area (VTA) dopaminergic (DAergic) neurons are considered to be engaged in reward and motivation. Here, we found that the VTA (DAergic)-mOT pathway could be activated by different types of naturalistic rewards as well as odors in DAT-cre mice. Optogenetic activation of the VTA-mOT DAergic fibers was able to elicit preferences for space, location and neutral odor, while pharmacological blockade of the dopamine receptors in the mOT fully prevented the odor-preference formation. Furthermore, inactivation of the mOT-projecting VTA DAergic neurons eliminated the previously formed odor-preference and strongly affected the Go-no go learning efficiency. In summary, our results revealed that the VTA (DAergic)-mOT pathway mediates a variety of naturalistic reward processes and different types of preferences including odor-preference in mice.
Topics: Animals; Behavior, Animal; Dopaminergic Neurons; Mice; Neural Pathways; Odorants; Olfactory Tubercle; Optogenetics; Ventral Tegmental Area
PubMed: 29251597
DOI: 10.7554/eLife.25423 -
Urologia Internationalis 1991In 69 dogs with divided hypogastric nerves anesthetized with ketamine and chloralose the outflows of the pelvic vesical branch (PV) and pudendal urethral branch (PU)...
Effects of amygdaloid and olfactory tubercle stimulation on efferent activities of the vesical branch of the pelvic nerve and the urethral branch of the pudendal nerve in dogs.
In 69 dogs with divided hypogastric nerves anesthetized with ketamine and chloralose the outflows of the pelvic vesical branch (PV) and pudendal urethral branch (PU) were recorded, and effects of amygdaloid and olfactory tubercle stimulation on them were studied. Stimulation (2-100 Hz, 3 ms, 0.2 mA) was applied to the amygdaloid body and olfactory tubercle. When the bladder contraction was induced by amygdaloid stimulation, the increased PV and decreased PU appeared after latencies of about 115 and 110 ms, respectively. When the bladder relaxation was, oppositely, elicited by stimulation, the decreased PV and enhanced PU occurred after latencies of 110 and 90 ms, respectively. The PV excitation was elicited by medial parts of the intermediate principal nucleus, medial parts of the medial principal nucleus, a part of cortical nucleus and of pericortical nucleus. Inhibition of PV was induced by lateral parts of the medial principal nucleus, medial nucleus, central nucleus and a part of the pericortical nucleus. Olfactory tubercle stimulation elicited PV excitation and PU inhibition with latencies of about 100 ms. The vesicopressor response from the tubercle was not abolished by section of the medial preoptic area, medial hypothalamus and periaqueductal gray, but was abolished by added section of the lateral preoptic area, lateral hypothalamus and lateral mesencephalic tegmentum. At the rostral pontine level, the response was abolished by partial section of the lateral part of the pontine reticular formation ipsilateral to the stimulation.
Topics: Amygdala; Animals; Dogs; Efferent Pathways; Electric Stimulation; Olfactory Bulb; Pons; Reaction Time; Synaptic Transmission; Urethra; Urinary Bladder; Urination
PubMed: 1659014
DOI: 10.1159/000282244 -
Current Biology : CB Jul 2018Critical animal behaviors, especially among rodents, are guided by odors in remarkably well-coordinated manners, yet many extramodal sensory cues compete for cognitive...
Critical animal behaviors, especially among rodents, are guided by odors in remarkably well-coordinated manners, yet many extramodal sensory cues compete for cognitive resources in these ecological contexts. That rodents can engage in such odor-guided behaviors suggests that they can selectively attend to odors. Indeed, higher-order cognitive processes-such as learning, memory, decision making, and action selection-rely on the proper filtering of sensory cues based on their relative salience. We developed a behavioral paradigm to reveal that rats are capable of selectively attending to odors in the presence of competing extramodal stimuli. We found that this selective attention facilitates accurate odor-guided decisions, which become further strengthened with experience. Further, we uncovered that selective attention to odors adaptively sharpens their representation among neurons in the olfactory tubercle, an olfactory cortex region of the ventral striatum that is considered integral for evaluating sensory information in the context of motivated behaviors. Odor-directed selective attention exerts influences during moments of heightened odor anticipation and enhances odorant representation by increasing stimulus contrast in a signal-to-noise-type coding scheme. Together, these results reveal that rats engage selective attention to optimize olfactory outcomes. Further, our finding of attention-dependent coding in the olfactory tubercle challenges the notion that a thalamic relay is integral for the attentional control of sensory coding.
Topics: Animals; Attention; Decision Making; Male; Odorants; Olfactory Cortex; Olfactory Pathways; Olfactory Perception; Rats; Rats, Long-Evans; Smell
PubMed: 30056854
DOI: 10.1016/j.cub.2018.05.011 -
Brain Research Oct 2021Depression, rapid eye movement (REM) sleep behavior disorder, and altered olfaction are often present in Parkinson's disease. Our previous studies demonstrated the role...
Depression, rapid eye movement (REM) sleep behavior disorder, and altered olfaction are often present in Parkinson's disease. Our previous studies demonstrated the role of the olfactory bulb (OB) in causing REM sleep disturbances in depression. Furthermore, adenosine A receptors (AR) which are richly expressed in the OB, play an important role in the regulation of REM sleep. Caffeine, an adenosine A receptors and AR antagonist, and other AR antagonists were reported to improve olfactory function and restore age-related olfactory deficits. Therefore, we hypothesized that the AR neurons in the OB may regulate olfaction or odor-guided behaviors in mice. In the present study, we employed chemogenetics to specifically activate or inhibit neuronal activity. Then, buried food test and olfactory habituation/dishabituation test were performed to measure the changes in the mice's olfactory ability. We demonstrated that activation of OB neurons or OB AR neurons shortened the latency of buried food test and enhanced olfactory habituation to the same odors and dishabituation to different odors; inhibition of these neurons showed the opposite effects. Photostimulation of ChR2-expressing OB AR neuron terminals evoked inward current in the olfactory tubercle (OT) and the piriform cortex (Pir), which was blocked by glutamate receptor antagonists 2-amino-5-phosphonopentanoic acid and 6-cyano-7nitroquinoxaline-2,3-dione. Collectively, these results suggest that the OB mediates olfaction via AR neurons in mice. Moreover, the excitatory glutamatergic release from OB neurons to the OT and the Pir were found responsible for the olfaction-mediated effects of OB AR neurons.
Topics: Animals; Male; Mice; Mice, Inbred C57BL; Neurons; Odorants; Olfactory Bulb; Olfactory Cortex; Olfactory Perception; Piriform Cortex; Receptor, Adenosine A2A; Smell
PubMed: 34310936
DOI: 10.1016/j.brainres.2021.147590 -
Frontiers in Behavioral Neuroscience 2019Olfaction induces adaptive motivated behaviors. Odors associated with food induce attractive behavior, whereas those associated with dangers induce aversive behavior. We...
Olfaction induces adaptive motivated behaviors. Odors associated with food induce attractive behavior, whereas those associated with dangers induce aversive behavior. We previously reported that learned odor-induced attractive and aversive behaviors accompany activation of the olfactory tubercle (OT) in a domain- and cell type-specific manner. Odor cues associated with a sugar reward induced attractive behavior and c-fos expression in the dopamine receptor D1-expressing neurons (D1 neurons) in the anteromedial OT. In contrast, odor cues associated with electrical shock induced aversive behavior and c-fos expression in the pamine receptor D2-expressing neurons (D2 neurons) in the anteromedial OT, as well as the D1 neurons in the lateral OT. Here, we investigated whether the D1 and D2 neurons in the anteromedial OT play distinct roles in attractive or aversive behaviors, using optogenetic stimulation and real-time place preference (RTPP) tests. Mice expressing ChETA (ChR2/E123T)-enhanced yellow fluorescent protein (EYFP) in the D1 neurons in the anteromedial OT spent a longer time in the photo-stimulation side of the place preference chamber than the control mice expressing EYFP. On the other hand, upon optogenetic stimulation of the D2 neurons in the anteromedial OT, the mice spent a shorter time in the photo-stimulation side than the control mice. Local neural activation in the anteromedial OT during the RTPP tests was confirmed by c-fos mRNA expression. These results suggest that the D1 and D2 neurons in the anteromedial OT play opposing roles in attractive and aversive behaviors, respectively.
PubMed: 30930757
DOI: 10.3389/fnbeh.2019.00050 -
The Journal of Comparative Neurology Apr 1978The association and commissural fiber systems arising in the olfactory cortical areas caudal to the olfactory peduncle (the piriform cortex, nucleus of the lateral...
The association and commissural fiber systems arising in the olfactory cortical areas caudal to the olfactory peduncle (the piriform cortex, nucleus of the lateral olfactory tract, anterior cortical nucleus of the amygdala, periamygdaloid cortex and entorhinal cortex) have been studied utilizing horseradish peroxidase as both an anterograde and a retrograde axonal tracer. In the piriform cortex two sublaminae within layer II (IIa and IIb) layer III have been found to give rise to distinctly different projections. Retrograde cell labeling experiments indicate that the association fiber projection from layer IIb is predominatnly caudally directed, while the projection from layer III is predominantly rostrally directed. Cells in layer IIa project heavily to areas both caudal and rostral to the piriform cortex. The commissural fibers from the piriform cortex are largely restricted in their origin to layer IIb of the anterior part of the piriform cortex and in their termination on the contralteral side to the posterior part of the piriform cortex and adjacent olfactory cortical areas. A projection to the olfactory bulb has also been found to arise from cells in layers IIb and III of the ipsilateral piriform cortex, but not in layer IIa. In addition to those from the piriform cortex, association projections have also been found from other olfactory cortical areas. The nucleus of the lateral olfactory tract has a heavy bilateral projection to the medial part of the anterior piriform cortex and the lateral part of the olfactory tubercle (as well as a lighter projection to the olfactory bulb); both the anterior cortical nucleus of the amygdala and the periamygdaloid cortex project ipsilaterally to several olfactory cortical areas. The entorhinal cortex has been found to project to the medial parts of the olfactory tubercle and the olfactory peduncle. The olfactory tubercle is the only olfactory cortical area from which no association fiber systems (instrinsic or extrinsic) have been found to originate. A broad topographic organization exists in the distribution of the fibers from several of the olfactory areas. This is most obvious in the anterior part of the olfactory cortex, in which fibers from the more rostral areas (the anterior olfactory nucleus and the anterior piriform cortex) terminate in regions near the lateral olfactory tract, while those from more caudal areas (the posterior piriform cortex and the entorhinal cortex) terminate in areas further removed, both laterally and medially, from the tract. Projection to olfactory areas from the hypothalamus, thalamus, diagonal band, and biogenic amine cell groups have been briefly described.
Topics: Animals; Association; Brain Mapping; Functional Laterality; Histocytochemistry; Horseradish Peroxidase; Limbic System; Neural Pathways; Olfactory Bulb; Olfactory Nerve; Olfactory Pathways; Rats
PubMed: 632378
DOI: 10.1002/cne.901780408 -
Brain Research Feb 2003The relationship between changes in regional brain bioamine levels and the expression of intraspecies aggressive behavior was evaluated in two murine models. In one...
The relationship between changes in regional brain bioamine levels and the expression of intraspecies aggressive behavior was evaluated in two murine models. In one study, normal male mice were maintained either in aggregate (i.e., normal, intraspecies social behavioral controls) or isolated (i.e., developed, non-social intraspecies aggressive 'fighter' behavior) housing environments, and the accompanying changes in both olfactory tubercle (OT) and hypothalamic (HYPOTH), norepinephrine (NE), dopamine (DA) and serotonin (5-HT) concentration indices quantitated by high-performance liquid chromatography (HPLC) for analysis of behavior-related alterations in localized bioamine deposition loci. Intact mice which had been housed in isolation cages and which exhibited aggressive, intraspecies reflexive-biting ('fighter') behavior when introduced to a novel (stimulus) animal, exhibited significant (P<0.05) elevations in NE levels, and depressed DA concentrations, in the OT regions relative to aggregated controls, indicating an intrinsic social influence on the maintenance of basal adrenergic indices at this neural locus. No changes in 5-HT levels were indicated between control and aggressive, isolated 'fighter' groups in either OT or HYPOTH loci. In addition, the NE and DA levels in the HYPOTH samples of both control and aggressive groups were found to be comparable. In the second study, utilizing an alternate type of aggression-induced murine model, changes in bioamine parameters were determined from samples obtained from aggregated, olfactory-bulbectomized (Obx) mice which are recognized to exhibit an overt, intraspecies, reflexive-biting behavior as compared to sham-operated (control) mice housed under identical conditions. In these studies, Obx-mice exhibited a significant increase in 5-HT levels in the OT relative to sham-operated controls, but similar NE and DA concentrations. In addition, all hypothalamic bioamine indices were found to be comparable between control and Obx groups. These data, collected for both isolation-developed, and experimentally-induced (i.e., OBX), intraspecies aggressive models, indicate that the distinctive types of aggressive behaviors displayed by these two murine models are accompanied by specific alterations in regional bioamine levels within the OT of these groups, relative to controls. These data suggest that the specific type of overt aggressive behavior demonstrated by these models may be causally related to the identified changes in bioamine concentrations in the forebrain regions of the CNS, in loci recognized to participate in environmental recognition and social processing activities.
Topics: Aggression; Animals; Biogenic Amines; Chromatography, High Pressure Liquid; Dopamine; Hypothalamus; Male; Mice; Motor Activity; Norepinephrine; Olfactory Bulb; Serotonin
PubMed: 12560120
DOI: 10.1016/s0006-8993(02)03963-x -
Cells, Tissues, Organs 2004The olfactory region was investigated in 303 serially sectioned human embryos, 23 of which were controlled by precise graphic reconstructions. The following findings in...
The olfactory region was investigated in 303 serially sectioned human embryos, 23 of which were controlled by precise graphic reconstructions. The following findings in the embryonic period are new for the human. (1) The nasal plates arise at the neurosomatic junction, as do also the otic placodes. (2) Crest comes from the nasal plates later (stage 13) than the maximum production in the neural folds (stage 10). (3) The crest arises and migrates during a much longer time (at least until the end of the embryonic period) than the neural crest of the head, where origin and migration end at stage 12. (4) Olfactory nerve fibres enter the brain at stage 17, the vomeronasal fibres and those of the nervus terminalis at stages 17 and 18. (5) Fibre connections between the olfactory tubercle and the olfactory bulb, as well as those to the amygdaloid nuclei, forebrain septum, and hippocampus, develop during and after stage 17. (6) Mitral cells appear late in the embryonic period. (7) Localized, although incomplete, lamination of the olfactory bulb is detectable at the embryonic/fetal transition. (8) Tangential migratory streams of neurons, from stage 22 to the early fetal period, proceed from the subventricular zone of the olfactory bulb towards the future claustrum; they remain within the insular region but are separated from the cortical plate. (9) In future cebocephaly morphological indications may be visible as early as stage 13. The various findings are integrated by means of staging, and current information for the fetal period is tabulated from the literature.
Topics: Embryonic Development; Gestational Age; Humans; Olfactory Pathways; Organogenesis; Time Factors
PubMed: 15604533
DOI: 10.1159/000081720 -
The Journal of Neuroscience : the... May 2020Rodents can successfully learn multiple novel stimulus-response associations after only a few repetitions when the contingencies predict reward. The circuits modified...
Rodents can successfully learn multiple novel stimulus-response associations after only a few repetitions when the contingencies predict reward. The circuits modified during such reinforcement learning to support decision-making are not known, but the olfactory tubercle (OT) and posterior piriform cortex (pPC) are candidates for decoding reward category from olfactory sensory input and relaying this information to cognitive and motor areas. Through single-cell recordings in behaving male and female C57BL/6 mice, we show here that an explicit representation for reward category emerges in the OT within minutes of learning a novel odor-reward association, whereas the pPC lacks an explicit representation even after weeks of overtraining. The explicit reward category representation in OT is visible in the first sniff (50-100 ms) of an odor on each trial, and precedes the motor action. Together, these results suggest that the coding of stimulus information required for reward prediction does not occur within olfactory cortex, but rather in circuits involving the olfactory striatum. Rodents are olfactory specialists and can use odors to learn contingencies quickly and well. We have found that mice can readily learn to place multiple odors into rewarded and unrewarded categories. Once they have learned the rule, they can do such categorization in a matter of minutes (<10 trials). We found that neural activity in olfactory cortex largely reflects sensory coding, with very little explicit information about categories. By contrast, neural activity in a brain region in the ventral striatum is rapidly modified in a matter of minutes to reflect reward category. Our experiments set up a paradigm for studying rapid sensorimotor reinforcement in a circuit that is right at the interface of sensory input and reward areas.
Topics: Animals; Female; Male; Mice; Mice, Inbred C57BL; Neurons; Olfactory Perception; Olfactory Tubercle; Piriform Cortex; Reward
PubMed: 32321744
DOI: 10.1523/JNEUROSCI.2604-19.2020