PSYC 211 Chapter Notes - Chapter 5: Methylene Blue, Photographic Emulsion, Autoradiograph
Document Summary
Experimental ablation/lesion study: removal/destruction of portion of brain to evaluate subsequent behavior. Evaluating behavioral effects of damage: lesion studies used to infer function of brain parts based on behavior animal can"t perform. Circuits in brain does functions, not behavior; each region does function, contributes to behavior. Interpretation complicated b/c regions interconnected; can"t conclude that function performed by neurons in x; may interfere w/ operation of circuits in y (septum links hippocampus, disrupts maternal behavior) Making lesions: electric current passed through wire w/ un-insulated tip. Guide wire stereotaxically, turn on rf current, heat kills everything near tip, inc. neural cell bodies, axons nearby. Excitotoxic lesions use amino acid (kainic), stim. neurons to death, selective det. if behavioral effects caused by death of neurons or nearby axons. 6-hd: more specific, selectively taken up by axons/buttons of noradrenergic/ dopaminergic neurons, poison from inside. Sham lesions: placebo, duplicate all steps except actual damage. For temporary/reversible lesion: local anesthetic (blocks potentials in axons), muscimol (stim.