Seasonal ataxia was reported in humans following the consumption of
Anaphe venata
larva as protein
supplement in diet and altered motor function in rodents when the extract was administered intraperitoneally. In this study
we investigated the effect of the crude aqueous and Phosphate Buffer Saline (PBS) extracts of
this larva on altered
spontaneous rat behavior in a novel environment particularly chewing behaviour, with a view to determine the
mechanism(s) involved in these behavioural alteration. Animals were randomly assigned into four groups (n = 6-12 per
group) and graded doses of aqueous and PBS extracts (100-400 mg/kg) were administered dissolved in saline
intraperitoneally (i.p.) to each animal in the experimental groups. The control group received an equivalent volume of
saline. Behavioral scores were recorded for a period of 30 minutes after the administration of saline or extract. The role of
various receptors in the extract induced chewing was evaluated using known receptor agonist/antagonists. Results revealed
a significant increase in purposeless chewing (F
(7, 95) = 7.85; p<0.05) by the aqueous extract compared to saline control at
all dose levels, which was significantly attenuated by scopolamine (3 mg/kg, i.p) and thiamine (1 mg/kg, i.p) respectively
(p<0.05); while flumazenil (2 mg/kg, i.p) and naloxone (2.5 mg/kg, i.p) did not alter the induced purposeless chewing
behaviour. Also, administration of PBS induced a significant (F
(7, 95) = 6.11; p<0.05) increase in chewing behaviour but
only at 400 mg/kg dose level which was attenuated by scopolamine (3 mg/kg, i.p); while flumazenil (2 mg/kg, i.p),
naloxone (2.5 mg/kg, i.p), and thiamine (1 mg/kg, i.p) potentiated purposeless chewing behaviour respectively. It may
therefore be concluded from this study that
Anaphe extract-induced purposeless chewing behaviour in rat is mediated via
the activation of cholinergic neurotransmission which is modulated by GABAergic and opioid receptor systems.
