scholarly journals Distinct roles of parvalbumin and somatostatin interneurons in gating the synchronization of spike times in the neocortex

2020 ◽  
Vol 6 (17) ◽  
pp. eaay5333 ◽  
Author(s):  
Hyun Jae Jang ◽  
Hyowon Chung ◽  
James M. Rowland ◽  
Blake A. Richards ◽  
Michael M. Kohl ◽  
...  
Keyword(s):  
Computational Model ◽  
Single Unit ◽  
Barrel Cortex ◽  
Feedback Inhibition ◽  
Inhibitory Interneurons ◽  
Cortical Layers ◽  
Sensory Stimuli ◽  
Firing Rates ◽  
Single Unit Recordings

Synchronization of precise spike times across multiple neurons carries information about sensory stimuli. Inhibitory interneurons are suggested to promote this synchronization, but it is unclear whether distinct interneuron subtypes provide different contributions. To test this, we examined single-unit recordings from barrel cortex in vivo and used optogenetics to determine the contribution of parvalbumin (PV)– and somatostatin (SST)–positive interneurons to the synchronization of spike times across cortical layers. We found that PV interneurons preferentially promote the synchronization of spike times when instantaneous firing rates are low (<12 Hz), whereas SST interneurons preferentially promote the synchronization of spike times when instantaneous firing rates are high (>12 Hz). Furthermore, using a computational model, we demonstrate that these effects can be explained by PV and SST interneurons having preferential contributions to feedforward and feedback inhibition, respectively. Our findings demonstrate that distinct subtypes of inhibitory interneurons have frequency-selective roles in the spatiotemporal synchronization of precise spike times.

scholarly journals Distinct roles of parvalbumin and somatostatin interneurons in the synchronization of spike-times in the neocortex

2019 ◽  
Author(s):  
Hyun Jae Jang ◽  
Hyowon Chung ◽  
James M. Rowland ◽  
Blake A. Richards ◽  
Michael M. Kohl ◽  
...  
Keyword(s):  
Barrel Cortex ◽  
Feedback Inhibition ◽  
Spike Timing ◽  
Timing Synchronization ◽  
Inhibitory Interneurons ◽  
Sensory Stimuli ◽  
Firing Rates ◽  
Single Unit Recordings ◽  
Spatio Temporal

AbstractSynchronization of precise spike-times across multiple neurons carries information about sensory stimuli. Inhibitory interneurons are suggested to promote this synchronization, but it is unclear whether distinct interneuron subtypes provide different contributions. To test this, we examined single-unit recordings from barrel cortex in vivo and used optogenetics to determine the contribution of two classes of inhibitory interneurons: parvalbumin (PV)- and somatostatin (SST)-positive interneurons to spike-timing synchronization across cortical layers. We found that PV interneurons preferentially promote the synchronization of spike-times when instantaneous firing-rates are low (<12 Hz), whereas SST interneurons preferentially promote the synchronization of spike-times when instantaneous firing-rates are high (>12 Hz). Furthermore, using a computational model, we demonstrate that these effects can be explained by PV and SST interneurons having preferential contribution to feedforward and feedback inhibition, respectively. Our findings demonstrate that distinct subtypes of inhibitory interneurons have frequency-selective roles in spatio-temporal synchronization of precise spike-times.

FosGFP expression does not capture a sensory learning-related engram in superficial layers of mouse barrel cortex

2021 ◽  
Vol 118 (52) ◽  
pp. e2112212118
Author(s):  
Jiseok Lee ◽  
Joanna Urban-Ciecko ◽  
Eunsol Park ◽  
Mo Zhu ◽  
Stephanie E. Myal ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Barrel Cortex ◽  
Sensory Information ◽  
Learning Task ◽  
Early Gene ◽  
Sensory Stimuli ◽  
Association Learning ◽  
Neural Ensembles ◽  
Dependent Learning

Immediate-early gene (IEG) expression has been used to identify small neural ensembles linked to a particular experience, based on the principle that a selective subset of activated neurons will encode specific memories or behavioral responses. The majority of these studies have focused on “engrams” in higher-order brain areas where more abstract or convergent sensory information is represented, such as the hippocampus, prefrontal cortex, or amygdala. In primary sensory cortex, IEG expression can label neurons that are responsive to specific sensory stimuli, but experience-dependent shaping of neural ensembles marked by IEG expression has not been demonstrated. Here, we use a fosGFP transgenic mouse to longitudinally monitor in vivo expression of the activity-dependent gene c-fos in superficial layers (L2/3) of primary somatosensory cortex (S1) during a whisker-dependent learning task. We find that sensory association training does not detectably alter fosGFP expression in L2/3 neurons. Although training broadly enhances thalamocortical synaptic strength in pyramidal neurons, we find that synapses onto fosGFP+ neurons are not selectively increased by training; rather, synaptic strengthening is concentrated in fosGFP− neurons. Taken together, these data indicate that expression of the IEG reporter fosGFP does not facilitate identification of a learning-specific engram in L2/3 in barrel cortex during whisker-dependent sensory association learning.

scholarly journals Texture coarseness responsive neurons and their mapping in layer 2–3 of the rat barrel cortex in vivo

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Liora Garion ◽  
Uri Dubin ◽  
Yoav Rubin ◽  
Mohamed Khateb ◽  
Yitzhak Schiller ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Barrel Cortex ◽  
Fundamental Function ◽  
Tactile Information ◽  
Hierarchical Processing ◽  
Two Photon ◽  
Columnar Organization ◽  
Layer 2 ◽  
Single Unit Recordings

Texture discrimination is a fundamental function of somatosensory systems, yet the manner by which texture is coded and spatially represented in the barrel cortex are largely unknown. Using in vivo two-photon calcium imaging in the rat barrel cortex during artificial whisking against different surface coarseness or controlled passive whisker vibrations simulating different coarseness, we show that layer 2–3 neurons within barrel boundaries differentially respond to specific texture coarsenesses, while only a minority of neurons responded monotonically with increased or decreased surface coarseness. Neurons with similar preferred texture coarseness were spatially clustered. Multi-contact single unit recordings showed a vertical columnar organization of texture coarseness preference in layer 2–3. These findings indicate that layer 2–3 neurons perform high hierarchical processing of tactile information, with surface coarseness embodied by distinct neuronal subpopulations that are spatially mapped onto the barrel cortex.

scholarly journals Identification of a developmental switch in information transfer between whisker S1 and S2 cortex in mice

2021 ◽  
Author(s):  
Theofanis Karayannis ◽  
Linbi Cai ◽  
Jenq-Wei Yang ◽  
Shen-Ju Chou ◽  
Chia-Fang Wang ◽  
...  
Keyword(s):  
Information Transfer ◽  
Barrel Cortex ◽  
Wide Field ◽  
Sensory Stimuli ◽  
Knock Out ◽  
Electrophysiological Recordings ◽  
Primary Sensory Cortex ◽  
Animal Navigation ◽  
Knock Out Mice

The whiskers of rodents are a key sensory organ that provides critical tactile information for animal navigation and object exploration throughout life. Previous work has explored the developmental sensory-driven activation of the primary sensory cortex processing whisker information (wS1), also called barrel cortex. This body of work has shown that the barrel cortex is already activated by sensory stimuli during the first post-natal week. However, it is currently unknown when over the course of development these stimuli begin being processed by higher order cortical areas, such as secondary whisker somatosensory area (wS2). Here we investigate for the first time the developmental engagement of wS2 by sensory stimuli and the emergence of cortico-cortical communication from wS1 to wS2. Using in vivo wide-field imaging and electrophysiological recordings in control and conditional knock-out mice we find that wS1 and wS2 are able to process bottom-up information coming from the thalamus already right after birth. We identify that it is only at the end of the first post-natal week that wS1 begins to provide excitation into wS2, a connection which begins to acquire feed-forward inhibition characteristics after the second post-natal week. Therefore, we have uncovered a developmental window during which excitatory versus inhibitory functional connectivity between wS1 and wS2 takes place.

scholarly journals A versatile and modular tetrode-based device for single-unit recordings in rodent ex vivo and in vivo acute preparations

2020 ◽  
Vol 341 ◽  
pp. 108755
Author(s):  
Francisca Machado ◽  
Nuno Sousa ◽  
Patricia Monteiro ◽  
Luis Jacinto
Keyword(s):  
Single Unit ◽  
Ex Vivo ◽  
Single Unit Recordings

scholarly journals Corticothalamic gating of population auditory thalamocortical transmission in mouse

2019 ◽  
Author(s):  
Baher A. Ibrahim ◽  
Caitlin Murphy ◽  
Guido Muscioni ◽  
Aynaz Taheri ◽  
Georgiy Yudintsev ◽  
...  
Keyword(s):  
Receptive Field ◽  
Auditory Cortex ◽  
Cortical Neurons ◽  
Feedback Inhibition ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Linear Filter ◽  
Sensory Stimuli

AbstractSince the discovery of the receptive field, scientists have tracked receptive field structure to gain insights about mechanisms of sensory processing. At the level of the thalamus and cortex, this linear filter approach has been challenged by findings that populations of cortical neurons respond in a stereotyped fashion to sensory stimuli. Here, we elucidate a possible mechanism by which gating of cortical representations occurs. All-or-none population responses (here called “ON” and “OFF” responses) were observed in vivo and in vitro in the mouse auditory cortex at near-threshold acoustic or electrical stimulation. ON-responses were associated with previously-described UP states in the auditory cortex. OFF-responses in the cortex were only eliminated by blocking GABAergic inhibition in the thalamus. Opto- and chemogenetic silencing of NTSR-positive corticothalamic layer 6 (CTL6) neurons as well as the pharmacological blocking of the thalamic reticular nucleus (TRN) retrieved the missing cortical responses, suggesting that the corticothalamic feedback inhibition via TRN controls the gating of thalamocortical activity. Moreover, the oscillation of the pre-stimulus activity of corticothalamic cells predicted the cortical ON vs. OFF responses, suggesting that underlying cortical oscillation controls thalamocortical gating. These data suggest that the thalamus may recruit cortical ensembles rather than linearly encoding ascending stimuli and that corticothalamic projections play a key role in selecting cortical ensembles for activation.

scholarly journals Prediction-error neurons in circuits with multiple neuron types: Formation, refinement and functional implications

2021 ◽  
Author(s):  
Loreen Hertäg ◽  
Claudia Clopath
Keyword(s):  
Network Model ◽  
Prediction Error ◽  
Recurrent Network ◽  
Inhibitory Interneurons ◽  
Sensory Stimuli ◽  
Firing Rates ◽  
Sensory Inputs ◽  
Functional Implications ◽  
Inhibitory Plasticity ◽  
Biased Perception

AbstractPredictable sensory stimuli do not evoke significant responses in a subset of cortical excitatory neurons. Some of those neurons, however, change their activity upon mismatches between actual and predicted stimuli. Different variants of these prediction-error neurons exist and they differ in their responses to unexpected sensory stimuli. However, it is unclear how these variants can develop and co-exist in the same recurrent network, and how they are simultaneously shaped by the astonishing diversity of inhibitory interneurons. Here, we study these questions in a computational network model with three types of inhibitory interneurons. We find that balancing excitation and inhibition in multiple pathways gives rise to heterogeneous prediction-error circuits. Dependent on the network’s initial connectivity and distribution of actual and predicted sensory inputs, these circuits can form different variants of prediction-error neurons that are robust to network perturbations and generalize to stimuli not seen during learning. These variants can be learned simultaneously via homeostatic inhibitory plasticity with low baseline firing rates. Finally, we demonstrate that prediction-error neurons can support biased perception, we illustrate a number of functional implications, and we discuss testable predictions.

scholarly journals Chemical synaptic transmission onto superficial stellate cells of the mouse dorsal cochlear nucleus

2014 ◽  
Vol 111 (9) ◽  
pp. 1812-1822 ◽  
Author(s):  
Pierre F. Apostolides ◽  
Laurence O. Trussell
Keyword(s):  
Cochlear Nucleus ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Dorsal Cochlear Nucleus ◽  
Fine Tuning ◽  
In Vivo Studies ◽  
Inhibitory Synapses ◽  
Inhibitory Interneurons ◽  
Sensory Stimuli

The dorsal cochlear nucleus (DCN) is a cerebellum-like auditory brain stem region whose functions include sound localization and multisensory integration. Although previous in vivo studies have shown that glycinergic and GABAergic inhibition regulate the activity of several DCN cell types in response to sensory stimuli, data regarding the synaptic inputs onto DCN inhibitory interneurons remain limited. Using acute DCN slices from mice, we examined the properties of excitatory and inhibitory synapses onto the superficial stellate cell, a poorly understood cell type that provides inhibition to DCN output neurons (fusiform cells) as well as to local inhibitory interneurons (cartwheel cells). Excitatory synapses onto stellate cells activated both NMDA receptors and fast-gating, Ca2+-permeable AMPA receptors. Inhibition onto superficial stellate cells was mediated by glycine and GABAA receptors with different temporal kinetics. Paired recordings revealed that superficial stellate cells make reciprocal synapses and autapses, with a connection probability of ∼18–20%. Unexpectedly, superficial stellate cells co-released both glycine and GABA, suggesting that co-transmission may play a role in fine-tuning the duration of inhibitory transmission.

scholarly journals Somatostatin receptors (SSTR1-5) on inhibitory interneurons in the barrel cortex

2019 ◽  
Vol 225 (1) ◽  
pp. 387-401 ◽  
Author(s):  
Agnieszka Lukomska ◽  
Grzegorz Dobrzanski ◽  
Monika Liguz-Lecznar ◽  
Malgorzata Kossut
Keyword(s):  
Barrel Cortex ◽  
Cortical Plasticity ◽  
Somatostatin Receptors ◽  
Immunofluorescent Staining ◽  
Inhibitory Interneurons ◽  
Cortical Layers ◽  
Cortical Interneurons ◽  
Specific Proteins ◽  
Chemical Synapses ◽  
The Brain

AbstractInhibitory interneurons in the cerebral cortex contain specific proteins or peptides characteristic for a certain interneuron subtype. In mice, three biochemical markers constitute non-overlapping interneuron populations, which account for 80–90% of all inhibitory cells. These interneurons express parvalbumin (PV), somatostatin (SST), or vasoactive intestinal peptide (VIP). SST is not only a marker of a specific interneuron subtype, but also an important neuropeptide that participates in numerous biochemical and signalling pathways in the brain via somatostatin receptors (SSTR1-5). In the nervous system, SST acts as a neuromodulator and neurotransmitter affecting, among others, memory, learning, and mood. In the sensory cortex, the co-localisation of GABA and SST is found in approximately 30% of interneurons. Considering the importance of interactions between inhibitory interneurons in cortical plasticity and the possible GABA and SST co-release, it seems important to investigate the localisation of different SSTRs on cortical interneurons. Here, we examined the distribution of SSTR1-5 on barrel cortex interneurons containing PV, SST, or VIP. Immunofluorescent staining using specific antibodies was performed on brain sections from transgenic mice that expressed red fluorescence in one specific interneuron subtype (PV-Ai14, SST-Ai14, and VIP-Ai14 mice). SSTRs expression on PV, SST, and VIP interneurons varied among the cortical layers and we found two patterns of SSTRs distribution in L4 of barrel cortex. We also demonstrated that, in contrast to other interneurons, PV cells did not express SSTR2, but expressed other SSTRs. SST interneurons, which were not found to make chemical synapses among themselves, expressed all five SSTR subtypes.

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