Cytoskeletal Proteins/genetics; Dendrites/metabolism; Dentate Gyrus/metabolism; Nerve Tissue Proteins/genetics; RNA, Messenger/biosynthesis; Receptors, N-Methyl-D-Aspartate/metabolism; Synapses/metabolism; Synaptic Transmission/physiology; Animals; Cell Compartmentation/physiology; Cytoskeletal Proteins/drug effects; Cytoskeletal Proteins/metabolism; Dendrites/drug effects; Dendrites/ultrastructure; Dentate Gyrus/cytology; Dentate Gyrus/drug effects; Electroshock/adverse effects; Excitatory Amino Acid Antagonists/pharmacology; Male; Nerve Tissue Proteins/drug effects; Nerve Tissue Proteins/metabolism; Neuronal Plasticity/drug effects; Neuronal Plasticity/physiology; Perforant Pathway/cytology; Perforant Pathway/drug effects; Perforant Pathway/metabolism; RNA, Messenger/drug effects; Rats; Rats, Sprague-Dawley; Receptors, AMPA/antagonists & inhibitors; Receptors, AMPA/metabolism; Receptors, Metabotropic Glutamate/antagonists & inhibitors; Receptors, Metabotropic Glutamate/metabolism; Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors; Synapses/drug effects; Synapses/ultrastructure; Synaptic Transmission/drug effects