Projections from orbitofrontal cortex to anterior piriform cortex in the rat suggest a role in olfactory information processing

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.

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Olfactory information processing, odor-modulated behavior, and their plasticity in the moth Manduca sexta

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology ◽

10.1016/j.cbpa.2009.04.307 ◽

2009 ◽

Vol 153 (2) ◽

pp. S155-S156

Author(s):

John G. Hildebrand ◽

Joshua P. Martin ◽

Carolina E. Reisenman ◽

Hong Lei ◽

Jeffrey A. Riffell

Keyword(s):

Information Processing ◽

Manduca Sexta ◽

Olfactory Information

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Active information maintenance in working memory by a sensory cortex

10.1101/385393 ◽

2018 ◽

Cited By ~ 1

Author(s):

Xiaoxing Zhang ◽

Wenjun Yan ◽

Wenliang Wang ◽

Hongmei Fan ◽

Ruiqing Hou ◽

...

Keyword(s):

Working Memory ◽

Piriform Cortex ◽

Delay Period ◽

Sensory Cortex ◽

Critical Function ◽

Impaired Performance ◽

Anterior Piriform Cortex ◽

Electrophysiological Recordings ◽

Dual Task Paradigm ◽

The Brain

SummaryWorking memory is a critical function of the brain to maintain and manipulate information over delay periods of seconds. Sensory areas have been implicated in working memory; however, it is debated whether the delay-period activity of sensory regions is actively maintaining information or passively reflecting top-down inputs. We hereby examined the anterior piriform cortex, an olfactory cortex, in head-fixed mice performing a series of olfactory working memory tasks. Information maintenance is necessary in these tasks, especially in a dual-task paradigm in which mice are required to perform another distracting task while actively maintaining information during the delay period. Optogenetic suppression of the piriform cortex activity during the delay period impaired performance in all the tasks.Furthermore, electrophysiological recordings revealed that the delay-period activity of the anterior piriform cortex encoded odor information with or without the distracting task.Thus, this sensory cortex is critical for active information maintenance in working memory.

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Increased Intracellular Calcium in Rat Anterior Piriform Cortex in Response to Threonine After Threonine Deprivation

Journal of Neurophysiology ◽

10.1152/jn.1999.81.3.1147 ◽

1999 ◽

Vol 81 (3) ◽

pp. 1147-1149 ◽

Cited By ~ 9

Author(s):

Linda J. Magrum ◽

M. Anne Hickman ◽

Dorothy W. Gietzen

Keyword(s):

Amino Acid ◽

Intracellular Calcium ◽

Piriform Cortex ◽

Anterior Piriform Cortex ◽

Enhanced Activity ◽

Sustained Increase

Increased intracellular calcium in rat anterior piriform cortex in response to threonine after threonine deprivation The anterior piriform cortex (APC) may serve as the chemosensor for amino acid (AA) deficiency in rats. To investigate the mechanism by which the APC recognizes a limiting indispensable AA (IAA), we examined changes in intracellular calcium ([Ca2+]i) in APC slices after culture in medium with or without threonine (Thr) or lysine (Lys). The addition of 1 or 10 mM Thr to slices previously incubated in Thr-devoid medium resulted in a significant and sustained increase in [Ca2+]i compared to control slices; an effect not seen when isoleucine, another IAA, was added. Similar results were seen when lysine, but not threonine, was added to slices incubated in lysine-devoid medium. The rise in [Ca2+]iresulting from the addition of the limiting IAA to deficient slices may be linked to enhanced activity of the appropriate AA transporter. This is suggested by preliminary findings that serine, a small neutral AA that uses the same transporter as threonine, gave rise to an enhanced response in the Thr-deficient slice.

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Understanding olfactory information processing by combining a physiologically realistic model of the olfactory bulb and olfactory cortex

Flavour ◽

10.1186/2044-7248-3-s1-p4 ◽

2014 ◽

Vol 3 (S1) ◽

Author(s):

Simon O’Connor

Keyword(s):

Information Processing ◽

Olfactory Bulb ◽

Realistic Model ◽

Olfactory Cortex ◽

Olfactory Information

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A role for the anterior piriform cortex in early odor preference learning: evidence for multiple olfactory learning structures in the rat pup

Journal of Neurophysiology ◽

10.1152/jn.00072.2013 ◽

2013 ◽

Vol 110 (1) ◽

pp. 141-152 ◽

Cited By ~ 18

Author(s):

Gillian L. Morrison ◽

Christine J. Fontaine ◽

Carolyn W. Harley ◽

Qi Yuan

Keyword(s):

Nmda Receptors ◽

Ex Vivo ◽

Glutamate Release ◽

Piriform Cortex ◽

Long Term Potentiation ◽

Preference Learning ◽

Excitatory Postsynaptic Potential ◽

Adrenergic Blockade ◽

Odor Preference ◽

Anterior Piriform Cortex

cFos activation in the anterior piriform cortex (aPC) occurs in early odor preference learning in rat pups ( Roth and Sullivan 2005 ). Here we provide evidence that the pairing of odor as a conditioned stimulus and β-adrenergic activation in the aPC as an unconditioned stimulus generates early odor preference learning. β-Adrenergic blockade in the aPC prevents normal preference learning. Enhancement of aPC cAMP response element-binding protein (CREB) phosphorylation in trained hemispheres is consistent with a role for this cascade in early odor preference learning in the aPC. In vitro experiments suggested theta-burst-mediated long-term potentiation (LTP) at the lateral olfactory tract (LOT) to aPC synapse depends on N-methyl-d-aspartate (NMDA) receptors and can be significantly enhanced by β-adrenoceptor activation, which causes increased glutamate release from LOT synapses during LTP induction. NMDA receptors in aPC are also shown to be critical for the acquisition, but not expression, of odor preference learning, as would be predicted if they mediate initial β-adrenoceptor-promoted aPC plasticity. Ex vivo experiments 3 and 24 h after odor preference training reveal an enhanced LOT-aPC field excitatory postsynaptic potential (EPSP). At 3 h both presynaptic and postsynaptic potentiations support EPSP enhancement while at 24 h only postsynaptic potentiation is seen. LOT-LTP in aPC is excluded by odor preference training. Taken together with earlier work on the role of the olfactory bulb in early odor preference learning, these outcomes suggest early odor preference learning is normally supported by and requires multiple plastic changes at least at two levels of olfactory circuitry.

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Homomeric RDL and Heteromeric RDL/LCCH3 GABA Receptors in the Honeybee Antennal Lobes: Two Candidates for Inhibitory Transmission in Olfactory Processing

Journal of Neurophysiology ◽

10.1152/jn.00798.2009 ◽

2010 ◽

Vol 103 (1) ◽

pp. 458-468 ◽

Cited By ~ 31

Author(s):

Julien Pierre Dupuis ◽

Michaël Bazelot ◽

Guillaume Stéphane Barbara ◽

Sandrine Paute ◽

Monique Gauthier ◽

...

Keyword(s):

Information Processing ◽

Chloride Channel ◽

Gaba Receptors ◽

Gaba Receptor ◽

Chloride Channels ◽

Physiological Role ◽

Inhibitory Transmission ◽

Olfactory Information ◽

Whole Cell Patch Clamp ◽

Inward Currents

γ-Aminobutyric acid (GABA)–gated chloride channel receptors are abundant in the CNS, where their physiological role is to mediate fast inhibitory neurotransmission. In insects, this inhibitory transmission plays a crucial role in olfactory information processing. In an effort to understand the nature and properties of the ionotropic receptors involved in these processes in the honeybee Apis mellifera, we performed a pharmacological and molecular characterization of GABA-gated channels in the primary olfactory neuropile of the honeybee brain—the antennal lobe (AL)—using whole cell patch-clamp recordings coupled with single-cell RT-PCR. Application of GABA onto AL cells at −110 mV elicited fast inward currents, demonstrating the existence of ionotropic GABA-gated chloride channels. Molecular analysis of the GABA-responding cells revealed that both subunits RDL and LCCH3 were expressed out of the three orthologs of Drosophila melanogaster GABA-receptor subunits encoded within the honeybee genome (RDL, resistant to dieldrin; GRD, GABA/glycine-like receptor of Drosophila ; LCCH3, ligand-gated chloride channel homologue 3), opening the door to possible homo- and/or heteromeric associations. The resulting receptors were activated by insect GABA-receptor agonists muscimol and CACA and blocked by antagonists fipronil, dieldrin, and picrotoxin, but not bicuculline, displaying a typical RDL-like pharmacology. Interestingly, increasing the intracellular calcium concentration potentiated GABA-elicited currents, suggesting a modulating effect of calcium on GABA receptors possibly through phosphorylation processes that remain to be determined. These results indicate that adult honeybee AL cells express typical RDL-like GABA receptors whose properties support a major role in synaptic inhibitory transmission during olfactory information processing.

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