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A classification of fusiform neocortical interneurons (n = 60) was performed with an unsupervised cluster analysis based on the comparison of multiple electrophysiological and molecular parameters studied by patch-clamp and single-cell multiplex reverse transcription-PCR in rat neocortical acute slices. The multiplex reverse transcription-PCR protocol was(More)
The cellular mechanisms by which neuronal nicotinic cholinergic receptors influence many aspects of physiology and pathology in the neocortex remain primarily unknown. Whole-cell recordings and single-cell reverse transcription (RT)-PCR were combined to analyze the effect of nicotinic receptor agonists on different types of neurons in acute slices of rat(More)
Sensory information, relayed through the thalamus, arrives in the neocortex as excitatory input, but rapidly induces strong disynaptic inhibition that constrains the cortical flow of excitation both spatially and temporally. This feedforward inhibition is generated by intracortical interneurons whose precise identity and properties were not known. To(More)
A long-standing question in neurobiology is whether astrocytes respond to the neuronal release of neurotransmitters in vivo. To address this question, acutely isolated hippocampal slices were loaded with the calcium-sensitive dye Calcium Green-1 and the responses of the astrocytes to electrical stimulation of the Schaffer collaterals were monitored by(More)
Emotional arousal strengthens memory. This is most apparent in aversive conditioning, in which the stress-related neurotransmitter norepinephrine (NE) enhances associations between sensory stimuli and fear-inducing events. In contrast to conditioning, extinction decreases fear responses, and is thought to form a new memory. It is not known, however, whether(More)
Extinction of conditioned fear is an active learning process involving inhibition of fear expression. It has been proposed that fear extinction potentiates neurons in the infralimbic (IL) prefrontal cortex, but the cellular mechanisms underlying this potentiation remain unknown. It is also not known whether this potentiation occurs locally in IL neurons as(More)
In the brain, astrocytes are associated intimately with neurons and surround synapses. Due to their close proximity to synaptic clefts, astrocytes are in a prime location for receiving synaptic information from released neurotransmitters. Cultured astrocytes express a wide range of neurotransmitter receptors, but do astrocytes in vivo also express(More)
It is becoming increasingly clear that astrocytes play very dynamic and interactive roles that are important for the normal functioning of the central nervous system. In culture, astrocytes express many receptors coupled to increases in intracellular calcium ([Ca2+]i). In vivo, it is likely that these receptors are important for the modulation of astrocytic(More)
In the rat neocortex, a subset of GABAergic interneurons express the neuropeptide vasoactive intestinal peptide (VIP). Previously, we demonstrated that a population of VIPergic interneurons could be accurately identified by their irregular spiking (IS) pattern and their bipolar morphology. IS interneurons were studied in neocortical slices from(More)
In the adult cerebral cortex, the neurotransmitter GABA is strongly inhibitory, as it profoundly decreases neuronal excitability and suppresses the network propensity for synchronous activity. When fast, GABA(A) receptor (GABA(A)R)-mediated neurotransmission is blocked in the mature cortex, neuronal firing is synchronized via recurrent excitatory(More)