New evidence for neurotransmitter influences on brain development.
The early appearance of monoamine systems in the developing mammalian CNS suggests that they play a role in neural development. We review data from two model systems that provide compelling new evidence of this role. In one model system-in utero exposure to cocaine-specific and robust alterations are seen in dopamine-rich areas of the cerebral cortex, such as the anterior cingulate cortex: D1 receptor-G protein coupling is greatly reduced, the GABAergic system is altered and pyramidal dendrites undergo excessive growth. In a second model system-a transgenic mouse line in which the gene that encodes monoamine oxidase A (MAOA) is disrupted, resulting in excessively high 5-HT levels-barrels fail to form in the developing somatosensory cortex. Both models reveal the effects of very early manipulation of monoamines on forebrain development, and the long-term anomalies that persist into adulthood.
Levitt
P
P
Dept of Neurobiology, University of Pittsburgh School of Medicine, PA 15261, USA.
Harvey
J A
JA
Friedman
E
E
Simansky
K
K
Murphy
E H
EH
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000196:embryology / Q000254:growth & development*; D003042:Cocaine / Q000633:toxicity; D005260:Female; D051379:Mice; D008822:Mice, Transgenic; D018377:Neurotransmitter Agents / Q000502:physiology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects
D018377:Neurotransmitter Agents; D003042:Cocaine