ABSTRACT
This chapter discusses theoretical aspects of immunohistochemistry and limitations of the technique and descriptions of some of the different immunohistochemical detection systems currently in use by neuroscientists. It presents the idea of studying functional neuroanatomy of drug action, examples of how immunohistochemistry has been utilized to study receptors for neurotransmitters and hormones in the brain, neurotoxic effects of drugs, and expression of proteins that may reflect functions of specific neurons. An important aspect of understanding the functional neuroanatomy of drug actions in the brain is knowing their neuroanatomical targets of action. A number of receptors for neurotransmitters and neuroactive substances have been localized in brain using immunohistochemistry. Many neuroactive drugs act at receptors for neurotransmitters and hormones. The vast majority of immunohistochemical investigations are performed using indirect immunohistochemical techniques. In this methodology, unlabeled primary antibodies are allowed to react with tissues to form an antibody-antigen complex with tissue-bound antigen.
