Ascending pathways mediated by monoamine neurotransmitters regulate the firing mode of thalamocortical neurons and modulate the state of brain activity. We hypothesized that specific neuropeptides might have similar actions. The effects of vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) were tested on thalamocortical neurons using whole-cell pa...

The thalamus plays a central and dynamic role in information transmission and processing in the brain. Multiple studies reveal increasing association between schizophrenia and dysfunction of the thalamus, in particular the medial dorsal nucleus (MDN), and its projection targets. The medial dorsal thalamic connections to the prefrontal cortex are of particular interest, and explicit in vivo evid...

During the development of forebrain connectivity, ascending thalamocortical and descending corticofugal axons first intermingle at the pallial-subpallial boundary to form the internal capsule (IC). However, the identity of molecular cues that guide these axons remains largely unknown. Here, we show that the transmembrane protein Linx is robustly expressed in the prethalamus and lateral ganglion...

The thalamus serves as a gate that regulates the flow of sensory inputs to the neocortex, and this gate is controlled by neuromodulators from the brainstem reticular formation that are released during arousal. Here we show in rats that sensory-evoked responses were suppressed in the neocortex by activating the brainstem reticular formation and during natural arousal. Sensory suppression occurre...

This study tested the hypothesis that inhibitory actions are exerted by reticularis thalami (RE) neurons upon thalamocortical neurons. The RE neurons were recorded in the rostral pole and lateral districts of the nucleus, and were activated monosynaptically by cortical volleys. Thalamocortical neurons were identified antidromically in intralaminar and ventrolateral nuclei. During sleep with EEG...

Neonatal sensory deprivation induced by whisker trimming affects significantly the functional organization of receptive fields in adult barrel cortex. In this study, the effects of deprivation on thalamocortical synapses and on asymmetrical and symmetrical synapses not of thalamic origin were examined. Thalamocortical synapses were labeled by lesion-induced degeneration in adult (postnatal day ...

Neurons in layer 4 of the primary auditory cortex receive convergent glutamatergic inputs from thalamic and cortical projections that activate different groups of postsynaptic glutamate receptors. Of particular interest in layer 4 neurons are the Group II metabotropic glutamate receptors (mGluRs), which hyperpolarize neurons postsynaptically via the downstream opening of GIRK channels. This pro...

This article addresses the functional significance of the electrophysiological properties of thalamic neurons. We propose that thalamocortical activity, is the product of the intrinsic electrical properties of the thalamocortical (TC) neurons and the connectivity their axons weave. We begin with an overview of the electrophysiological properties of single neurons in different functional states,...

In the mammalian brain, thalamic signals reach the cortex via two major routes: primary and higher-order thalamocortical pathways. While primary thalamocortical nuclei transmit sensory signals from the periphery, the function of higher-order thalamocortical projections remains enigmatic, in particular their role in sensory processing in the cortex. Here, by optogenetically controlling the thala...

The perturbational complexity index (PCI) measures the spatiotemporal dynamics of transcranial magnetic stimulation (TMS)-evoked electroencephalography (EEG) potentials (TEPs) [1]. High PCI values reflect joint presence integration and differentiation in thalamocortical networks conscious brains Low have been reported during natural non-rapid eye movement sleep, disorders consciousness, unrespo...