Physiological and Morphological Characterization ofOrganotypic Cocultures of the Chick Forebrain AreaMNH and its Main Input Area DMA/DMP

[摘要] Cocultures of the learning-relevant forebrainregion mediorostrai neostriatum andhyperstriatum ventrale (MNH) and its mainglutamatergic input area nucleus dorsomedialisanterior thalami/posterior thalami were morphologicallyand physiologically characterized.Synaptic contacts of thalamic fibers were lightandelectron-microscopically detected on MNHneurons by applying the fluorescence tracerDiI-C18(3) into the thalamus part of the coculture.Most thalamic synapses on MNH neuronswere symmetric and located on dendritic shafts,but no correlation between Gray-type ultrastructureand dendritic localization was found.Using intraceilular current clamp recordings, wefound that the electrophysiological properties,such as input resistance, time constant, actionpotential threshold, amplitude, and duration ofMNH neurons, remain stable for over 30 days invitro. Pharmacological blockade experimentsrevealed glutamate as the main neurotransmitterof thalamic synapses on MNH neurons, whichwere also found on inhibitory neurons. Highfrequency stimulation of thalamic inputs evokedsynaptic potentiation in22%of MNH neurons.The results indicate that DMA/DMP-MNH cocultures,which can be maintained under stableconditions for at least 4 weeks, provide anattractive in vitro model for investigatingsynaptic plasticity in the avian brain.

[学科分类] 精神健康和精神病学