Developmental alcohol exposure has been shown to affect the hippocampus, a brain region involved in learning and memory. Long-lasting alterations in synaptic plasticity and AMPA receptor (AMPAR) function have been shown to be a consequence of developmental ethanol (EtOH) exposure. Precocious AMPAfication of synaptic connections can prematurely stabilize neuronal connections. Previous studies in the neonatal hippocampus have demonstrated that alcohol exposure increases network activity, strengthens AMPAR-mediated transmission in a neurosteroid-dependent manner, and decreases cells displaying silent synapses. Together, these data implicate that EtOH alters the normal developmental course of AMPAR- mediated synaptic transmission in CA1 hippocampal pyramidal neurons, and therefore it is hypothesized that developmental exposure to EtOH will strengthen AMPAR-mediated function in CA1 hippocampal pyramidal neurons during the third trimester equivalent of human pregnancy.
Specific aim 1 : is to determine if developmental EtOH exposure alters AMPAR function and subunit expression in CA1 pyramidal neurons. Using the rat alcohol vapor inhalation paradigm, EtOH exposure during the human third-trimester equivalent will be modeled. AMPAR function and expression will be investigated using whole-cell patch-clamp and immunohistochemical techniques. AMPAR-mediated synaptic currents, current- voltage (IV) relationships, and AMPAR subunit expression will be investigated.
Specific aim 2 : is to determine if developmental EtOH exposure affects plasticity in CA1 pyramidal neurons. Studies of long term potentiation (LTP), as well as neuronal expression of silent synapses will be used to address this possibility. The proposed studies will lead to a better understanding of the effects of EtOH on AMPAR- mediated function in the immature hippocampus, making contributions to the FASD as well as the developmental fields, and eventually may lead to the discovery of effective therapies for the life-long consequences of FASD.
|Puglia, Michael P; Valenzuela, C Fernando (2010) Ethanol acutely inhibits ionotropic glutamate receptor-mediated responses and long-term potentiation in the developing CA1 hippocampus. Alcohol Clin Exp Res 34:594-606|
|Puglia, Michael P; Valenzuela, C Fernando (2010) Repeated third trimester-equivalent ethanol exposure inhibits long-term potentiation in the hippocampal CA1 region of neonatal rats. Alcohol 44:283-90|
|Puglia, Michael P; Valenzuela, Carlos Fernando (2009) AMPAR-mediated synaptic transmission in the CA1 hippocampal region of neonatal rats: unexpected resistance to repeated ethanol exposure. Alcohol 43:619-25|