Methods for culturing adult CNS neurons reveal a CNS conditioning effect

Researchers have developed methods for culturing adult central nervous system neurons in large numbers and across multiple brain regions for extended time periods. Primary adult neuronal cultures develop polarity; they establish segregated dendritic and axonal compartments, maintain resting membrane potentials, exhibit spontaneous and evoked electrical activity, and form neural networks. Cultured adult neurons isolated from different brain regions such as the hippocampus, cortex, brainstem, and cerebellum exhibit distinct cell morphologies, growth patterns, and spontaneous firing characteristics reflective of their regions of origin. Using adult motor cortex cultures, we identify a CNS ‘‘conditioning’’ effect after spinal cord injury. The ability to culture adult neurons offers a valuable tool for studying basic and therapeutic science of the brain.

• 1
  Adult neurons in culture from various brain regions retained several features characteristic of their in vivo cell morphology, including distinct morphologies for motor cortex, cerebellar Purkinje, hippocampal, reticulospinal, and spinal cord alpha motor neurons.
• 2
  Cultured adult neurons exhibited spontaneous and evoked electrophysiological activity, demonstrating synaptic activity and correlated network activity in both cortical and hippocampal cultures.
• 3
  A highly significant central conditioning effect was observed: animals that received a spinal cord injury 24 h before preparation of motor cortex cultures exhibited a 4-fold increase in total neurite outgrowth compared with cortical neurons from controls that did not have a preceding spinal cord lesion.