Excitotoxins ibotenic acid

Arbogast RE, Kozlowski MR. (1988). Quantitative morphometric analysis of the neurotoxic effects of the excitotoxin, ibotenic acid, on the basal forebrain. /Veurotox/co/ogy Spring. 9(1) 39-45. 

After kainic acid, ibotenic acid has been the most extensively characterized of the excitotoxins effective with local injection. On a molar basis, ibotenic acid has approximately 20-fold lower potency than kainic acid... 

The maturity of brain plays an important role in neuronal vulnerability to excitotoxins. The CVO regions and neural retina of immature rats and mice (less than 10 days of age) are much more sensitive to peripherally administered excitotoxins than the adult. In contrast, the striatum of the neonatal rat is remarkably resistant to doses of kainic acid that produce extensive lesions in the adult but full vulnerability is attained by three weeks after birth (Campochiaro and Coyle, 1978). Similarly, Honnegar and Richelson (1977) have found that reaggregating brain cultures exhibit increasing sensitivity to the neurotoxic effects of kainic acid with differentiation. At the other extreme, neuronal sensitivity of the striatum to directly injected kainate appears to increase with advancing age (Gaddy et aL, 1979). An age dependence for the neurotoxic action of ibotenic acid and other directly injected excitotoxins has not yet been described. 

Moreover, there are similarities between the behavioural changes following lead exposure and those seen after hippocampal damage (Alfano and Petit, 1981). Therefore, a direct comparison between lesioned animals and lead-exposed ones is desirable. For this purpose ibotenic acid, an excitotoxin, was used to induce chemical lesions of intrinsic neurons to the hippocampus only, while fibres of passage and afferents were spared. Lesioned animals were compared with animals exposed to low levels of lead. 

---