Figure 5.

Cultured neurons exhibit TβR-II immunoreactivity. Neurons were isolated and allowed to grow for 5 days before fixation. Immunoreactivity was visualized with a rhodamine-conjugated rabbit-anti-goat IgG. (A) Sensory neurons from the ventral–caudal cluster of the pleural ganglion grown in culture with no postsynaptic target exhibit immunoreactivity along the cell body and neurites. (B) Control cultures show little staining. (C) Not all sensory neurons exhibit the same intensity of immunoreactivity. Note that these sensory neurons exhibit higher levels of immunoreactivity than that in A. (D) Cocultured sensory neuron and L7, an identified motor neuron. The synaptic connection was verified by extracellularly stimulating the sensory neuron and recording an EPSP in the motor neuron (not shown). Both cell bodies are immunostained as well as the major axons of each neuron and finer neuronal processes. Scale bars, 30 μm.