GLUTAMATE METABOLISM IN OCTOPUS BRAIN IN VIVO;ABSENCE OF A WAELSCH EFFECT

Abstract— The metabolism of U-¹⁴C]glutamate was followed in vivo in the octopus Eledone cirrhosa following intracranial injection, and compared with that in the mammalian brain.
By contrast with the rat brain, the specific activity of glutamine recovered from Eledone optic and vertical lobes was lower than that of glutamate at short time intervals after injection. Thus the Waelsch effect was not apparent in this species. Again, in contrast with the rat brain, radioactivity could be found in alanine but not in GABA following U-¹⁴C]glutamate injection. This was compatible with observations made previously in vitro.
The significance of these intraspecies differences in metabolism and compartmentation is discussed.