| The brain is composed of excitatory and inhibitory neurons. One class of inhibitory neurons transmit an inhibitory signal in response to the neurotransmitter yAminobutyric acid (GABA), to which excitatory neurons do not respond. These so-called "GABAergic" neurons are the major inhibitory neurons in the brain. GABAergic inhibitory activity maintains the balance that is disrupted in conditions such as epilepsy. GABAergic neurons are initially excitatory and subsequently convert to inhibitory; this transition remains unclear. To probe any role of sensory input, we stimulated neuronal networks established on multi-electrode arrays. Developing networks display progressively organized signaling. Stimulation for 5 days hastened, while stimulation for 1 day delayed, organized signaling. GABA treatment reduced total signals in unstimulated networks and networks stimulated for 5 days, but not in networks stimulated for 1 day. These findings suggest that continuous sensory input fosters the developmental transition of GABAergic neurons into inhibitory neurons. |
