Random stimulation of spider mechanosensory neurons reveals long-lasting excitation by GABA and muscimol Running Head: Excitatory actions of GABA

Muscimol Reveals Long-Lasting Excitation by GABA and Random Stimulation of Spider Mechanosensory Neurons

Random stimulation of spider mechanosensory neurons reveals long-lasting excitation by GABA and muscimol.

gamma-Aminobutyric acid type A (GABA(A)) receptor activation inhibits many primary afferent neurons by depolarization and increased membrane conductance. Deterministic (step and sinusoidal) functions are commonly used as stimuli to test such inhibition. We found that when the VS-3 mechanosensory neurons innervating the spider lyriform slit-sense organ were stimulated by randomly varying white-n...

Inhibitory glutamate receptors in spider peripheral mechanosensory neurons.

Most mechanosensory neurons are inhibited by GABAergic efferent neurons. This inhibition is often presynaptic and mediated by ionotropic GABA receptors at the axon terminals. GABA receptor activation opens Cl- channels, leading to membrane depolarization and an increase in membrane conductance. In many invertebrate preparations, efferent neurons that innervate mechanosensory afferents contain g...

GABA and glutamate receptors have different effects on excitability and are differentially regulated by calcium in spider mechanosensory neurons.

GABA and glutamate receptors belonging to the ligand-gated chloride-channel family are primary targets of insecticides and antiparasitics, so their molecular structure, pharmacology and biophysical properties have attracted significant attention. However, little is known about the physiological roles of these channels or how they regulate neuronal excitability and animal behavior. Mechanosensor...

Activation of GABAA receptors modulates all stages of mechanoreception in spider mechanosensory neurons.

GABA(A) receptors mediate mainly inhibitory effects, but there are also many examples of excitatory effects in both mammalian and invertebrate preparations. Here, we aimed to create a complete, quantitative picture of GABA(A)-mediated excitation in a mechanosensory neuron where this phenomenon has been well established. We used muscimol to activate GABA(A) receptors in spider VS-3 neurons and m...