In situ hybridization of whole-mounts of Aplysia ganglia using non-radioactive probes.

A protocol for carrying out in situ hybridization with non-radioactive, digoxigenin-labelled probes has been developed for whole-mounts of Aplysia ganglia. Whole-mount preparations preserve the anatomical relationships of neurons within intact ganglia and facilitate the precise identification of a particular neuron in live preparations so that functional studies can be correlated with biochemical attributes of an identified neuron. The protocol was developed with the use of probes to messenger RNAs that are abundant in Aplysia neurons. In situ hybridization with a cDNA probe to a neuronal form of beta-actin stained all neurons, including their processes, whereas use of a cDNA probe for the neuropeptide FMRFamide resulted in staining of a select group of Aplysia neurons.