Jf. Flood et al., LOCALIZED INJECTIONS OF VARIOUS COMPOUNDS EFFECTING NEUROTRANSMITTER ACTIVITY IN THE MAMMILLARY COMPLEX ENHANCE (T-MAZE) AVOIDANCE RETENTION, European journal of pharmacology, 275(3), 1995, pp. 223-228
The mammillary complex is implicated in the amnesic syndrome associate
d clinically with Korsakoff's syndrome, Alzheimer's disease and experi
mentally with lesions in animals. There is however no direct evidence
that the mammillary bodies are involved in long term memory processing
. Mice were partially trained on a footshock avoidance task. Immediate
ly after training drugs were injected into the mammillary complex, Ret
ention was tested 1 week later by continuing training until each mouse
made five avoidance responses in six trials. The results indicated th
at muscarine, nicotine, dopamine, glutamine and adrenoceptor agonists
as well as GABA and 5-HT receptor antagonists and neuropeptide Y impro
ved retention test performance relative to the control. Injection of t
he same drugs 1 mm above the injection site for the mammillary complex
failed to significantly improve retention test performance, It is con
cluded that the mammillary complex, with its important connections to
other areas of the limbic system, is involved in memory processing eve
nts that occur shortly after training,