Effects of D-galactosamine and D-glucosamine on retention performance of a brightness discrimination task in rats.
The glycoprotein and ganglioside precursors D-galactosamine and D-glucosamine were tested for effects on acquisition and retention of a brightness discrimination reaction in rats. Intraperitoneally (1.85 mmoles/kg) and intraventricularly (0.8 mumoles) applied D-galactosamine had no influence on acquisition, but improved the retention performance. Intraperitoneally (6.0 mmoles/kg) and intraventricularly (2.4 mumoles) applied D-glucosamine showed qualitatively identical results, i.e. improving effect on retention performance. The penetration abilities of [3H]D-glucosamine and [3H]N-acetyl-D-glucosamine to cross the blood-brain barrier were tested: D-glucosamine penetrated easily the blood-brain barrier (approximately 2:1 relation). However, after intravenous application of 200 mumoles 30 min before training both substances showed a positive effect on retention performance. The findings are discussed in the light that the retention-improving effects of the hexosamines under investigation are believed to be due to a direct, activating influence on glycoprotein and/or ganglioside syntheses in the brain.
D000606:Amino Sugars / Q000378:metabolism; D000818:Animals; D001923:Brain Chemistry; D004192:Discrimination, Psychological / Q000187:drug effects*; D004597:Electroshock; D005688:Galactosamine / Q000494:pharmacology*; D005944:Glucosamine / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008027:Light; D008297:Male; D008568:Memory / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012153:Retention, Psychology / Q000187:drug effects*; D012794:Sialic Acids / Q000378:metabolism
D000606:Amino Sugars; D012794:Sialic Acids; D005688:Galactosamine; D005944:Glucosamine