scholarly journals Sharp wave-associated synchronized inputs from the piriform cortex activate olfactory tubercle neurons during slow-wave sleep

2014 ◽  
Vol 111 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Kimiya Narikiyo ◽  
Hiroyuki Manabe ◽  
Kensaku Mori
Keyword(s):  
Slow Wave ◽  
Olfactory System ◽  
Slow Wave Sleep ◽  
Piriform Cortex ◽  
Current Source ◽  
Olfactory Tubercle ◽  
Neuronal Circuitry ◽  
Anterior Piriform Cortex ◽  
Sharp Waves ◽  
Density Analysis

During slow-wave sleep, anterior piriform cortex neurons show highly synchronized discharges that accompany olfactory cortex sharp waves (OC-SPWs). The OC-SPW-related synchronized activity of anterior piriform cortex neurons travel down to the olfactory bulb and is thought to be involved in the reorganization of bulbar neuronal circuitry. However, influences of the OC-SPW-related activity on other regions of the central olfactory system are still unknown. Olfactory tubercle is an area of OC and part of ventral striatum that plays a key role in reward-directed motivational behaviors. In this study, we show that in freely behaving rats, olfactory tubercle receives OC-SPW-associated synchronized inputs during slow-wave sleep. Local field potentials in the olfactory tubercle showed SPW-like activities that were in synchrony with OC-SPWs. Single-unit recordings showed that a subpopulation of olfactory tubercle neurons discharged in synchrony with OC-SPWs. Furthermore, correlation analysis of spike activity of anterior piriform cortex and olfactory tubercle neurons revealed that the discharges of anterior piriform cortex neurons tended to precede those of olfactory tubercle neurons. Current source density analysis in urethane-anesthetized rats indicated that the current sink of the OC-SPW-associated input was located in layer III of the olfactory tubercle. These results indicate that OC-SPW-associated synchronized discharges of piriform cortex neurons travel to the deep layer of the olfactory tubercle and drive discharges of olfactory tubercle neurons. The entrainment of olfactory tubercle neurons in the OC-SPWs suggests that OC-SPWs coordinate reorganization of neuronal circuitry across wide areas of the central olfactory system including olfactory tubercle during slow-wave sleep.

scholarly journals Temporal coordination of olfactory cortex sharp-wave activity with up- and downstates in the orbitofrontal cortex during slow-wave sleep

2017 ◽  
Vol 117 (1) ◽  
pp. 123-135 ◽  
Author(s):  
Naomi Onisawa ◽  
Hiroyuki Manabe ◽  
Kensaku Mori
Keyword(s):  
Slow Wave ◽  
Orbitofrontal Cortex ◽  
Slow Wave Sleep ◽  
Time Windows ◽  
Late Phase ◽  
Piriform Cortex ◽  
Olfactory Cortex ◽  
Field Potentials ◽  
Temporal Coordination ◽  
Anterior Piriform Cortex

During slow-wave sleep, interareal communications via coordinated, slow oscillatory activities occur in the large-scale networks of the mammalian neocortex. Because olfactory cortex (OC) areas, which belong to paleocortex, show characteristic sharp-wave (SPW) activity during slow-wave sleep, we examined whether OC SPWs in freely behaving rats occur in temporal coordination with up- and downstates of the orbitofrontal cortex (OFC) slow oscillation. Simultaneous recordings of local field potentials and spike activities in the OC and OFC showed that during the downstate in the OFC, the OC also exhibited downstate with greatly reduced neuronal activity and suppression of SPW generation. OC SPWs occurred during two distinct phases of the upstate of the OFC: early-phase SPWs occurred at the start of upstate shortly after the down-to-up transition in the OFC, whereas late-phase SPWs were generated at the end of upstate shortly before the up-to-down transition. Such temporal coordination between neocortical up- and downstates and olfactory system SPWs was observed between the prefrontal cortex areas (OFC and medial prefrontal cortex) and the OC areas (anterior piriform cortex and posterior piriform cortex). These results suggest that during slow-wave sleep, OC and OFC areas communicate preferentially in specific time windows shortly after the down-to-up transition and shortly before the up-to-down transition. NEW & NOTEWORTHY Simultaneous recordings of local field potentials and spike activities in the anterior piriform cortex (APC) and orbitofrontal cortex (OFC) during slow-wave sleep showed that APC sharp waves tended to occur during two distinct phases of OFC upstate: early phase, shortly after the down-to-up transition, and late phase, shortly before the up-to-down transition, suggesting that during slow-wave sleep, olfactory cortex and OFC areas communicate preferentially in the specific time windows.

scholarly journals Sharp wave-associated activity patterns of olfactory cortical neurons in the mouse piriform cortex

2018 ◽  
Author(s):  
Kazuki Katori ◽  
Hiroyuki Manabe ◽  
Ai Nakashima ◽  
Eer Dunfu ◽  
Takuya Sasaki ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Slow Wave Sleep ◽  
Activity Patterns ◽  
Piriform Cortex ◽  
Associative Memories ◽  
Firing Rates ◽  
Anterior Piriform Cortex ◽  
Sharp Wave ◽  
Sharp Waves ◽  
Neural Activities

ABSTRACTThe olfactory piriform cortex is thought to participate in olfactory associative memory. Like the hippocampus, which is essential for episodic memory, it belongs to an evolutionally conserved paleocortex and comprises a three-layered cortical structure. During slow-wave sleep, the olfactory piriform cortex becomes less responsive to external odor stimuli and instead displays sharp wave (SPW) activity similar to that observed in the hippocampus. Neural activity patterns during hippocampal SPW have been intensively studied in terms of memory consolidation; however, little is known about the activity patterns of olfactory cortical neurons during olfactory cortex sharp waves (OC-SPWs). In this study, we recorded multi-unit neural activities in the anterior piriform cortex in urethane-anesthetized mice. We found that the activity patterns of olfactory cortical neurons during OC-SPWs were non-randomly organized. Individual olfactory cortical neurons varied in the timings of their peak firing rates during OC-SPW events. Moreover, specific pairs of olfactory cortical neurons were more frequently activated together than expected by chance. On the basis of these observations, we speculate that coordinated activation of specific subsets of olfactory cortical neurons repeats during OC-SPWs, thereby facilitating synaptic plasticity underlying the consolidation of olfactory associative memories.

scholarly journals The Neurotransmitter Receptor Architecture of the Mouse Olfactory System

2021 ◽  
Vol 15 ◽  
Author(s):  
Kimberley Lothmann ◽  
Katrin Amunts ◽  
Christina Herold
Keyword(s):  
Olfactory System ◽  
Piriform Cortex ◽  
Hierarchical Cluster ◽  
Distribution Patterns ◽  
Olfactory Cortex ◽  
Cluster Solution ◽  
Olfactory Tubercle ◽  
Neurotransmitter Receptor ◽  
Heterogeneous Expression

The uptake, transmission and processing of sensory olfactory information is modulated by inhibitory and excitatory receptors in the olfactory system. Previous studies have focused on the function of individual receptors in distinct brain areas, but the receptor architecture of the whole system remains unclear. Here, we analyzed the receptor profiles of the whole olfactory system of adult male mice. We examined the distribution patterns of glutamatergic (AMPA, kainate, mGlu2/3, and NMDA), GABAergic (GABAA, GABAA(BZ), and GABAB), dopaminergic (D1/5) and noradrenergic (α1 and α2) neurotransmitter receptors by quantitative in vitro receptor autoradiography combined with an analysis of the cyto- and myelo-architecture. We observed that each subarea of the olfactory system is characterized by individual densities of distinct neurotransmitter receptor types, leading to a region- and layer-specific receptor profile. Thereby, the investigated receptors in the respective areas and strata showed a heterogeneous expression. Generally, we detected high densities of mGlu2/3Rs, GABAA(BZ)Rs and GABABRs. Noradrenergic receptors revealed a highly heterogenic distribution, while the dopaminergic receptor D1/5 displayed low concentrations, except in the olfactory tubercle and the dorsal endopiriform nucleus. The similarities and dissimilarities of the area-specific multireceptor profiles were analyzed by a hierarchical cluster analysis. A three-cluster solution was found that divided the areas into the (1) olfactory relay stations (main and accessory olfactory bulb), (2) the olfactory cortex (anterior olfactory cortex, dorsal peduncular cortex, taenia tecta, piriform cortex, endopiriform nucleus, entorhinal cortex, orbitofrontal cortex) and the (3) olfactory tubercle, constituting its own cluster. The multimodal receptor-architectonic analysis of each component of the olfactory system provides new insights into its neurochemical organization and future possibilities for pharmaceutic targeting.

Membrane currents evoked by afferent fiber stimulation in rat piriform cortex. I. Current source-density analysis

1993 ◽  
Vol 69 (1) ◽  
pp. 248-260 ◽  
Author(s):  
K. L. Ketchum ◽  
L. B. Haberly
Keyword(s):  
Pyramidal Cell ◽  
Piriform Cortex ◽  
Current Source ◽  
Afferent Fiber ◽  
Companion Paper ◽  
Current Source Density ◽  
Anterior Piriform Cortex ◽  
Source Density ◽  
Apical Dendrites ◽  
Fiber Stimulation

1. The membrane currents evoked by afferent fiber stimulation in the piriform cortex were derived by the use of current source-density (CSD) analysis in the rat under urethan anesthesia. The primary goals were to test hypotheses concerning the sequence of synaptic events evoked by afferent fiber stimulation and to derive data required for development and testing of the model presented in the companion paper. 2. In confirmation of previous studies, it was found that afferent fiber stimulation evokes a monosynaptic excitatory postsynaptic current (EPSC) in distal segments of pyramidal cell apical dendrites (layer Ia) followed by a strong disynaptic EPSC in adjacent middle segments (superficial layer Ib). 3. Given the central importance of the strong disynaptic EPSC in models for operation of the piriform cortex, the hypothesis that it is mediated by long association fibers from the anterior piriform cortex was tested by comparing its latency in response to stimulation at anterior and posterior locations. The results confirmed the hypothesis and ruled out a significant contribution from local connections in the posterior piriform cortex. 4. Intensification of pyramidal cell activity by spatially restricted disinhibition with picrotoxin confirmed the hypothesis that associational projections from the posterior piriform cortex can mediate a long-latency disynaptic EPSC in proximal dendritic segments (mid to deep layer Ib) in the anterior piriform cortex. 5. Analysis of the time course of the monosynaptic EPSC in different areas revealed that activation of the anterior piriform cortex from afferent fiber stimulation is fast and nearly synchronous throughout its extent as a result of the relatively high conduction velocities of afferent fibers in the lateral olfactory tract (LOT). By contrast, the posterior piriform cortex is sequentially activated by this EPSC as a consequence of the slow propagation velocity of afferent fiber collaterals that course across its surface. This activation is sufficiently slow that a large phase lag is present between rostral and caudal regions. 6. The time courses of the monosynaptic and principal disynaptic EPSCs changed in characteristically different ways with increasing distance from the LOT within the posterior piriform cortex. Simulations in the companion paper indicate that initiation and propagation patterns for activity in fiber systems rather than differences in synaptic conductance waveforms are responsible for these differences. 7. Although the laminar distribution of the active inward current component of the monosynaptic EPSC remained constant over time, the peak outward current associated with this EPSC shifted from the depth of proximal apical dendrites (layer Ib) to the depth of superficial pyramidal cell somata (layer II).(ABSTRACT TRUNCATED AT 400 WORDS)

Olfactory cortex generates sharp waves during slow-wave sleep

2010 ◽  
Vol 68 ◽  
pp. e390
Author(s):  
Ikue Kusumoto-Yoshida ◽  
Hiroyuki Manabe ◽  
Mizuho Ota ◽  
Kensaku Mori
Keyword(s):  
Slow Wave ◽  
Slow Wave Sleep ◽  
Olfactory Cortex ◽  
Sharp Waves

Olfactory Inputs Activate the Medial Entorhinal Cortex Via the Hippocampus

2000 ◽  
Vol 83 (4) ◽  
pp. 1924-1931 ◽  
Author(s):  
Gerardo Biella ◽  
Marco de Curtis
Keyword(s):  
Entorhinal Cortex ◽  
Piriform Cortex ◽  
Current Source ◽  
Lateral Olfactory Tract ◽  
Medial Entorhinal Cortex ◽  
Source Density ◽  
Entorhinal Region ◽  
Current Source Density Analysis ◽  
Density Analysis ◽  
Olfactory Input

The lateral and medial regions of the entorhinal cortex differ substantially in terms of connectivity and pattern of activation. With regard to olfactory input, a detailed and extensive physiological map of the olfactory projection to the entorhinal cortex is missing, even if anatomic studies suggest that the olfactory afferents are confined to the lateral and rostral entorhinal region. We studied the contribution of the medial and lateral entorhinal areas to olfactory processing by analyzing the responses induced by lateral olfactory tract stimulation in different entorhinal subfields of the in vitro isolated guinea pig brain. The pattern of synaptic activation of the medial and lateral entorhinal regions was reconstructed either by performing simultaneous multisite recordings or by applying current source density analysis on field potential laminar profiles obtained with 16-channel silicon probes. Current source density analysis demonstrated the existence of a direct monosynaptic olfactory input into the superficial 300 μm of the most rostral part of the lateral entorhinal cortex exclusively, whereas disynaptic sinks mediated by associative fibers arising from the piriform cortex were observed at 100–350 μm depth in the entire lateral aspect of the cortex. No local field responses were recorded in the medial entorhinal region unless a large population spike was generated in the hippocampus (dentate gyrus and CA1 region) by a stimulus 3–5× the intensity necessary to obtain a maximal monosynaptic response in the piriform cortex. In these conditions, a late sink was recorded at a depth of 600-1000 μm in the medial entorhinal area (layers III–V) 10.6 ± 0.9 (SD) msec after a population spike was simultaneously recorded in CA1. Diffuse activation of the medial entorhinal region was also obtained by repetitive low-intensity stimulation of the lateral olfactory tract at 2–8 Hz. Higher or lower stimulation frequencies did not induce hippocampal-medial entorhinal cortex activation. These results suggest that the medial and the lateral entorhinal regions have substantially different roles in processing olfactory sensory inputs.

scholarly journals Sleep-Like States Modulate Functional Connectivity in the Rat Olfactory System

2010 ◽  
Vol 104 (6) ◽  
pp. 3231-3239 ◽  
Author(s):  
Donald A. Wilson ◽  
Xiaodan Yan
Keyword(s):  
Functional Connectivity ◽  
Olfactory Bulb ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
Dorsal Hippocampus ◽  
Piriform Cortex ◽  
Field Potential ◽  
Wave State ◽  
State Dependent ◽  
Hippocampal Activity

The present study was an examination of state-dependent functional connectivity during spontaneous activity between the piriform cortex and its upstream and downstream connections. Rats were anesthetized with urethan and allowed to spontaneously cycle between fast- and slow-wave states similar to fast- and slow-wave sleep states. Local field potential recordings were made from the olfactory bulb, piriform cortex, dorsal hippocampus, amygdala, and primary visual cortex. The results demonstrate that during slow-wave sleep-like states, when the piriform cortex shows reduced sensitivity to odor input via the olfactory bulb, there is enhanced coherence with other forebrain structures. Granger causality analyses suggest that the link between piriform cortical and hippocampal activity during slow-wave state is in the direction of the hippocampus to the piriform cortex rather than the reverse. The results suggest that slow-wave sleep-like states may provide an opportunity for the transfer and/or consolidation of information related to odor memories, specifically at a time when the piriform cortex is less sensitive to sensory input.

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