Can neurotoxins make your brain nerve cells over excited ?

Usually the opposite: Majority of neurotoxins cause neuronal dysfunction or even cell death. Excitatory Amino Acids are involved in cell damage following ischemia or trauma. Excitation of nerve cells results from neurotransmitter signalling. Chemical and electric (hard-wired) feedbacks help avoid over-excitation of neurons. These safety switches may be altered or even overrun by a variety of stimulants.

Neurotoxins: Neurotoxins work in a number of different ways depending on the toxin and that can include stopping the nerve from doing its normal function to overdriving the nerve which can lead to a poorly functioning nervous system. They a number of different toxins and none of them are good for your brain or nerve cells.