In this study, we describe the development of electrical properties of @entity238 embryonic central neurons in vivo. Using whole-cell voltage clamp, we describe the onset of expression of specific voltage- and ligand-gated ionic currents and the first appearance of endogenous and synaptic activity. The first currents occur during midembryogenesis [late stage 16, 13-14 hr @entity18947 ( @entity18947 )] and consist of a delayed outward @entity972 current (IK) and an @entity934 -gated inward cation current (IACh). As development proceeds, other voltage-activated currents arise sequentially. An inward @entity460 current (ICa) is first observed at 15 hr @entity18947 , an inward @entity1372 current (INa) at 16 hr @entity18947 , and a rapidly inactivating outward @entity972 current (IA) at 17 hr @entity18947 . The inward @entity460 current is composed of at least two individual and separable components that exhibit small temporal differences in their development. Endogenous activity is first apparent at 15 hr @entity18947 and consists of small events (peak amplitude, 5 pA) that probably result from the random opening of relatively few numbers of ion channels. At 16 hr @entity18947 , discrete (10-15 msec duration) currents that exhibit larger amplitude (25 pA maximum) and rapid activation but slower inactivation first appear. We identify these latter currents as EPSCs, an indication that functional synaptic transmission is occurring. In the neurons from which we record, action potentials first occur at 17 hr @entity18947 . This study is the first to record from @entity238 embryonic central neurons in vivo and makes possible future work to define the factors that shape the electrical properties of neurons during development.

Electrophysiological development of central neurons in the XXXX embryo.

@entity1372 :: ('MESH:D012964', 'Chemical') :: ['sodium'] @entity460 :: ('MESH:D002118', 'Chemical') :: ['calcium'] @entity972 :: ('MESH:D011188', 'Chemical') :: ['potassium'] @entity238 :: ('7227', 'Species') :: ['Drosophila'] @entity18947 :: ('MESH:D021181', 'Disease') :: ['after egg laying', 'AEL'] @entity934 :: ('MESH:D000109', 'Chemical') :: ['acetylcholine']
@entity238 :: (7227,Species) :: ['Drosophila']
