Regenerating adult cockroach dorsal unpaired median neurones in vitro retain their in vivo membrane characteristics

The ability of differentiated neurones to recover from disease or injury depends upon both intrinsic and extrinsic factors. Whereas most mammalian neurones have a limited capacity for regeneration, regulated, in part, by physical and chemical cues in the brain microenvironment (Bray et al. 1987; Caroni and Schwab, 1988, 1989), invertebrates, and in particular insects, exhibit a far greater capacity for repair of central neurones and circuits (Treherne et al. 1988). Studies of the cues that regulate the regenerative process are made easier by the use of individual, identified neurones, cultured under controlled conditions. Invertebrates are particularly useful in this regard; neurones from mature nervous systems of both annelids and molluscs have been grown successfully in culture and their growth can be influenced by changes in the culture conditions (Acklin and Nicholls, 1990; Dagan and Levitan, 1981; Ready and Nicholls, 1979; Syed et al. 1990). Routine and long-term culture of identified neurones from the insect central nervous system (CNS) has proved more elusive, preventing the use of neurones from these well-studied systems. Recently, however, cultures of cockroach (Howes et al. 1991), locust (Kirchoff and Bicker, 1992) and moth (Hayashi and Levine, 1992) adult neurones have been described.