title: Prenatal development of gabaergic, glycinergic, and dopaminergic neurons in the rabbit retina.
abstract: The main findings from our studies on the emergence and maturation of neurotransmitter systems in the rabbit retina are that, during normal development: (1) the commitments for certain neurons to become GABAergic, glycinergic, or dopaminergic are made prenatally; the maturation of these neurons, however, occurs postnatally; (2) specific accumulations of exogenously supplied transmitters by presumed retinal neurons were first observed autoradiographically around embryonic day 22 (E22) for gamma-aminobutyric acid (GABA), E25 for glycine, and E27 for dopamine, suggesting that putative GABAergic, glycinergic, and dopaminergic neurons are determined phenotypically at least by these days; (3) based upon the three transmitter-specific properties--uptake, synthesis, and release--the uptake property is generally the first to emerge, while the appearance of the other properties follows a precise and distinct temporal pattern for each of the transmitters studied; (4) for GABAergic and glycinergic systems, the emergence of K+-stimulated, Ca2+-dependent release mechanisms occurs many days after the first appearance of the uptake properties; in contrast, the mechanisms for dopamine uptake and release emerge at about the same time; and (5) by our criteria, putative GABAergic and glycinergic amacrine cells are mature between postnatal day 10 (P10) and P12, around the time when the eyes first open and direction-selective ganglion cells can first be recorded; however, the dopaminergic neurons probably are not mature until about P24.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001345:Autoradiography; D004298:Dopamine / Q000502:physiology; D005260:Female; D005998:Glycine / Q000502:physiology; D011817:Rabbits; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000502:physiology*; D011954:Receptors, Dopamine / Q000502:physiology*; D018009:Receptors, Glycine; D012160:Retina / Q000166:cytology / Q000196:embryology* / Q000254:growth & development; D005680:gamma-Aminobutyric Acid / Q000502:physiology
chemical_list: D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D011954:Receptors, Dopamine; D018009:Receptors, Glycine; D005680:gamma-Aminobutyric Acid; D005998:Glycine; D004298:Dopamine