Demonstration of three different types of chemosensitive units in the crayfish claw using a computerized evaluation.

The different types of single units, sensitive either to amino acids, amines or 'pyridines' were found in afferent neurones in the claw of Orconectes limosus. The shape of action potentials and the pattern of nerve impulse discharge were characteristic for each type. A computer program used in simultaneous recordings from several units selects up to four units according to spike amplitudes and establishes post-stimulus-time histograms, time interval histograms and average time courses of action potentials for each unit.