Whereas the basic wiring diagram of the mammalian central nervous system (CNS) is
genetically preprogramed, its fine tuning throughout different phases of infancy, childhood, and
adulthood are highly experience dependent. The potential neurobiological mechanisms and
behavioral effects of such experience-dependent neuroplasticity as a function of stage of
development are outlined. A basic thesis of this paper is that mechanisms involved in neuronal
learning and memory, such as long-term potentiation (LTP) and long-term depression (LTD), are
used and reused not only in the sculpting of the CNS in the initial establishment of connections,
but also again in the molding of personality and behavior based on experience. It is postulated
that for higher order processes such as emotional memory, such neuroplasticity is occurring at
increasingly larger numbers of synapses and cell assemblies with increasing mechanistic
complexity and self-organization. Just as overexcitation or deprivation can profoundly affect the
development of the visual system, it is postulated that similar phenomena exist in the neural
substrates of emotional and cognitive development. In addition, a secondary and potentially more
widespread series of ramifications are likely to occur in the higher order and integrative systems,
such as secondary and tertiary cortical association areas and prefrontal cortex that become the
ultimate integrators of emotion and experience, leading to subsequent actions and plans for the
future. This process is, by definition, plastic, and such remodeling is likely to take place not only
at the level of the single synapse, but also at higher levels of network integration of which we
currently have only the barest glimpse. Nonetheless, beginning to discuss the neurobiology of
such self-organizing plastic systems may begin to change our conceptual approaches to
psychopathology and open new avenues of therapeutics for the major psychiatric illnesses that
are critically dependent on such higher order learning and memory mechanisms.