Neuron
We studied the role of desensitization at inhibitory synapses by comparing nonequilibrium GABA A channel gating with inhibitory postsynaptic currents (IPSCs). Currents activated by brief pulses of 1-10 mM GABA to outside-out patches from cultured hippocampal neurons mimicked GABA-mediated IPSCs. Although the average open time of single GABA A channels following brief pulses was less...
The emergence of functional lateral interactions in ferret visual cortex was monitored using high speed optical imaging of voltage-sensitive dye signals in brain slices. Prior to the time of eye opening, lateral activation was restricted to a narrow columnar region. During the week following eye opening, the extent of lateral propagation of activity more than doubled. Selective interruption of specific...
In five members of a family and another unrelated person affected by a slow-channel congenital myasthenic syndrome (SCCMS), molecular genetic analysis of acetylcholine receptor (AChR) subunit genes revealed a heterozygous G to A mutation at nucleotide 457 of the α subunit, converting codon 153 from glycine to serine (αG153S). Electrophysiologic analysis of SCCMS end plates revealed prolonged decay...
Recording of glutamate-activated currents in membrane patches was combined with RT-PCR-mediated AMPA receptor (AMPAR) subunit mRNA analysis in single identified cells of rat brain slices. Analysis of AMPARs in principal neurons and interneurons of hippocampus and neocortex and in auditory relay neurons and Bergmann glial cells indicates that the GluR-B subunit in its flip version determines formation...
Sensory transduction in vertebrate photoreceptors and olfactory sensory neurons is mediated by cyclic nucleotide-gated (CNG) channels that conduct mono- anddivalent cations. Ca 2 + entering the cell through CNG channels intimately controls signaling pathways by regulating several key enzymes. Cloned CNG channels from photoreceptors and olfactory sensory neurons profoundly differ in their...
The mechanisms that regulate regional specification and evolution of the cerebral cortex are obscure. To this end, we have identified and characterized a novel murine and human gene encoding a putative transcription factor related to the Brachyury (T) gene that is expressed only in postmitotic cells. T-brain-1 (Tbr-1) mRNA is largely restricted to the cerebral cortex, where during embryogenesis it...
Homologs of the Drosophila clock gene per have recently been cloned in Lepidopteran and Blattarian insect species. To assess the extent to which clock mechanisms are conserved among phylogenetically distant species, we determined whether PER protein from the silkmoth Antheraea pernyi can function in the Drosophila circadian timing system. When expressed in transgenic Drosophila, the silkmoth PER protein...
Excitatory synaptic activity in horizontal stratum oriens-alveus interneurons (OAIs) is driven by the recurrent collaterals of CA1 pyramidal cells and is strongly influenced by protocols that elicit synaptic plasticity in these principal neurons. Induction of LTD in the Schaffer collateral-CAI pyramidal neuron synapse causes a passive down-regulation of stratum radiatum-evoked excitatory synaptic...
Midbrain dopaminergic neurons, whose loss in adults results in Parkinson's disease, can be specified during embryonic development by a contact-dependent signal from floor plate cells. Here we show that the aminoterminal product of Sonic hedgehog autoproteolysis (SHH-N), an inductive signal expressed by floor plate cells, can induce dopaminergic neurons in vitro. We show further that manipulations...
The acetylcholine receptor from vertebrate skeletal muscle is a pentamer of homologous subunits with composition α 2 βγδ. Its two ligand binding sites, formed at α-γ and α-δ interfaces, differ in their affinities for agonists and competitive antagonists, owing to different contributions of the γ and δ subunits. To identify portions of the and δ subunits that contribute to the binding sites,...
To identify molecules that regulate the transition of dividing neuroblasts to terminally differentiated neurons in the CNS, conditions have been developed that allow the neuronal differentiation of cortical precursor cells to be examined in vitro. In these cultures, the proliferation of undifferentiated precursor cells is controlled by basic fibroblast growth factor (bFGF). The proliferative effects...
Relatively little is known about the neural circuitry underlying sex-specific behaviors. We have expressed the feminizing gene transformer in genetically defined subregions of the brain of male Drosophila, and in particular within different domains of the mushroom bodies. Mushroom bodies are phylogenetically conserved insect brain centers implicated in associative learning and various other aspects...
Phylogenetically conserved brain centers known as mushroom bodies are implicated in insect associative learning and in several other aspects of insect behavior. Kenyon cells, the intrinsic neurons of mushroom bodies, have been generally considered to be disposed as homogenous arrays. Such a simple picture imposes constraints on interpreting the diverse behavioral and computational properties that...