The neuromodulator adenosine is widely considered to be a key regulator of sleep homeostasis and an indicator of sleep need. Although the effect of adenosine on subcortical areas has been previously described, the effects on cortical neurons have not been addressed systematically to date. To that purpose, we performed in vitro whole-cell patch-clamp recordings and biocytin staining of pyramidal...

Expression of the transcriptional repressor Zbtb20 is confined to the hippocampal primordium of the developing dorsal midline cortex in mice. Here, we show that misexpression of Zbtb20 converts projection neurons of the subiculum and postsubiculum (dorsal presubiculum) to CA1 pyramidal neurons that are innervated by Schaffer collateral projections in ectopic strata oriens and radiatum. The Zbtb...

Buhler, A. V. and T. V. Dunwiddie. 7 nicotinic acetylcholine receptors on GABAergic interneurons evoke dendritic and somatic inhibition of hippocampal neurons. J Neurophysiol 87: 548–557, 2002; 10.1152/jn.00316.2001. GABAergic interneurons in the hippocampus express high levels of 7 nicotinic acetylcholine receptors, but because of the diverse roles played by hippocampal interneurons, the impac...

It is postulated that synchronous firing of cortical neurons plays an active role in cognitive functions of the brain. An important issue is whether pyramidal neurons in different cortical layers exhibit similar tendencies to synchronise. To address this issue, we performed intracellular and whole-cell recordings of regular-spiking pyramidal neurons in slice preparations of the rat motor cortex...

Prefrontal cortex is a hub for attention processing and receives abundant innervation from cholinergic and serotonergic afferents. A growing body of evidence suggests that acetylcholine (ACh) and serotonin (5-HT) have opposing influences on tasks requiring attention, but the underlying neurophysiology of their opposition is unclear. One candidate target population is medial prefrontal layer 6 p...

The effect of Schaffer collateral/commissural fiber kindling on the expression levels of GABA A receptor ill, fiE, and f13 subunit mRNA in the pyramidal and granular neurons of the rat dorsal hippocampus was studied, using semi-quantitative in situ hybridization. In pyramidal neurons of CA1 and CA3, only small changes (10-15%) were found. In dentate granule neurons, the expression level of GABA...

Serotonin exerts a powerful influence on neuronal excitability. In this study, we investigated the effects of serotonin on different neuronal populations in prefrontal cortex (PFC), a major area controlling emotion and cognition. Using whole-cell recordings in PFC slices, we found that bath application of 5-HT dose-dependently increased the firing of FS (fast spiking) interneurons, and decrease...

During postnatal development of CA1 pyramidal neurons, GABAergic synapses are excitatory and established prior to glutamatergic synapses. As interneurons are generated before pyramidal cells, we have tested the hypothesis that the GABAergic interneuronal network is operative before glutamate pyramidal neurons and provides the initial patterns of activity. We patch-clamp recorded interneurons in...

Pyramidal neurons in layer VI of the primary motor and somatosensory cortices were examined by a combined method of intracellular recording, biocytin injection, and immunocytochemistry using in vitro slice preparations of rat brain. lmmunofluorescence staining revealed that biocytin-injected pyramidal cells in layer VI were separated into glutaminase (PAG)-immunopositive and PAG-immunonegative ...

The mechanisms responsible for seizure generation in cortical dysplasia (CD) are unknown, but morphologically abnormal cells could contribute. We examined the passive and active membrane properties of cells from pediatric CD in vitro. Normal- and abnormal-appearing cells were identified morphologically by using infrared videomicroscopy and biocytin in slices from children with mild to severe CD...