RT Journal Article
SR Electronic
T1 Development of chemosensitivity of an identified insect interneurone
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 1167
OP 1175
DO 10.1523/JNEUROSCI.05-05-01167.1985
VO 5
IS 5
A1 JM Blagburn
A1 DJ Beadle
A1 DB Sattelle
YR 1985
UL http://www.jneurosci.org/content/5/5/1167.abstract
AB Characteristic features of cockroach embryos (Periplaneta americana) are determined for different stages in development. Morphological changes in giant interneurone 2 (GI 2) in the terminal abdominal ganglion during embryogenesis are described based on cobalt injections. A sequential proliferation of branches preceded by filopodial extension is observed between 45 and 80% embryogenesis, by which time the characteristic arborization of the first instar cell is established. The cholinergic agonist carbamylcholine was ionophoretically applied to the cell body and dendritic region of GI 2 at various stages in development, and the responses were recorded intracellularly. Chemosensitivity of GI 2 appears at 40 to 45% embryogenesis, to a similar degree in both cell body and dendrites. The sensitivity of these areas subsequently diverges, and after the 60 to 65% stage, the dendrites are approximately 1000 times more sensitive than the cell body. At 80 to 85% embryogenesis, there is a temporary peak in dendritic sensitivity, and cell body sensitivity increases during postembryonic development. The changes in sensitivity take place before synaptogenesis, and the decline in dendritic sensitivity after the 80% stage may be related to synaptic maturation.