Acetylcholinesterase in the development of chick dorsal root ganglia

Abstract

Acetylcholinesterase is expressed in chick dorsal root ganglia neurons very early in development. Since the physiological role of the enzyme in these cells is still obscure, it appeared of interest to investigate its modifications in the course of development. The specific activity of acetylcholinesterase in chick dorsal root ganglia increases, during in ovo development, from day E5 to day E13; after day E13 there is a decrease. Conversely, when acetylcholinesterase activity was expressed on a per ganglion basis, a continuous increase in the level of the enzyme until day E20 was observed. Acetylcholinesterase is a polymorphic enzyme and its molecular forms have different cellular localizations. Two globular forms, a tetramer (G4) and a dimer (G2), are present in the ganglia, as in chick brain. G4 is the major form at day E5, where it represents about 85% of the activity. This form shows a progressive decrease since day E8, and at day E20 exhibits activity levels similar to those of G2. It is known that acetylcholinesterase-producing cells are also able to release the enzyme in the extracellular space. We determined the release of acetylcholinesterase by cultured dorsal root ganglia neurons at various developmental stages: acetylcholinesterase release is significantly increased at day E20, as compared to younger stages, and 90% of the enzyme released is G4.

Acetylcholinesterase antibody treatment results in neurite detachment and reduced outgrowth from cultured neurons: Further evidence for a cell adhesive role for neuronal acetylcholinesterase

“…In the avian embryo, Layer and colleagues (Layer, 1990(Layer, , 1991Layer and Kaulich, 1991) have shown a transient AChE expression in developing spinal cord neurons that progresses in a rostrocaudal wave, coinciding with periods of axonal outgrowth (Weikert et al, 1990). Temporary AChE expression has also been documented in developing dorsal root ganglion (DRG) neurons (Cochard and Coltey, 1983;Moody and Stein, 1988;Biagioni et al, 1989;Layer and Kaulich, 1991;Koenigsberger et al, 1998) and, later, in their axons and growth cones in the spinal cord (Tennyson and Brzin, 1970;Oudega and Marani, 1990).…”

Substratum‐induced modulation of acetylcholinesterase activity in cultured dorsal root ganglion neurons

“…Based on these observations, it has been proposed that AChE may have a novel, non-cholinergic role in morphogenetic movements and path-finding during development of the nervous system (Robertson, 1987;Hutchins and Casagrande, 1988;Kristt, 1989;Layer et al, 1988;Weikert et al, 1990). In this regard, we have demonstrated that inhibition of AChE activity retards neuritic outgrowth from cultured dorsal root ganglia neurons (DRGN), which express AChE activity, yet they are neither cholinergic nor cholinoceptive (Bigbee and Foster, 1989;Biagioni et al, 1989).To explore the possible interaction between AChE activity and environment we have studied the effect of substrata, with variable degrees of permissiveness to neuritic outgrowth, on the levels of AChE activity in Received March 28, 1991; revised June 18, 1991 …”

Morphogenic Role for Acetylcholinesterase in Axonal Outgrowth during Neural Development

“…Address correspondence to J. W. Bigbee axonal outgrowth from these cells (1,8,9). In the peripheral nervous system (PNS), AChE is transiently expressed by developing dorsal root ganglion (DRG) neurons (10)(11)(12)(13)(14) and later in their axons and growth cones in the spinal cord (15,16 (18). BW284c51 is a bis-quaternary nitrogen compound that is a highly specific inhibitor for AChE.…”