Bio Psych Exam 2 Part 3

Neurodegenerative and Psychiatric Disorders

Parkinson’s Disease

Parkinson’s disease- chronic, progressive neurodegenerative disorder characterized by:

•Tremors

•Akinesia- difficulty in initiation of movements

•Bradykinesia- slowed/reduced movements

•Rigidity- stiffness, inflexibility in the joints

•Postural instability- impaired balanced and coordination

Pathology of Parkinson’s Disease

•Pathology of PD is due to loss of DA cells in the SNc

•Excitotoxicity and inflammation

•mitochondrial dysfunction and oxidative stress, protein misfolding

•Formation of Lewy bodies which triggers apoptotic cell death

Caused by problems in the basal ganglia, specifically the substantia nigra having problems communicating with the caudate and putamen, which then have trouble communicating with the thalamus and subthalamic nucleus

Treatment for Parkinson’s Disease

Medications that increase DA transmission

•L-DOPA +decarboxylase inhibitors

•MAOIs

•COMT (catechol-o-methyl-transferase) inhibitors

•DA agonists

•DAT inhibitors

Depression with PD:

•SSRIs

•TCAs

•MAOIs

•Antipsychotic medications - selective 5-HT inverse agonists (for psychosis)

Pathology of Alzheimer’s Disease

• Basal forebrain can’t communicate with forebrain due to cholinergic system dysfunction

• Hippocampus can’t communicate, difficult to retrieve memories

• Brainstem cholinergic system disfunction - memory and learning issues

• Amyloid plaques and neurofibrillary tangles formed, inhibiting neuronal communication

Treatment for Alzheimer’s Disease

•Alzheimer’s disease targets cholinergic cells involved in cognition

•Cholinesterase inhibitors (Ach to choline)

•nACh and mACH agonists

•DA agonists for working memory

Dopamine Pathways relevant to Schizophrenia

• Overactivity of the mesolimbic pathway (VTA to Nucleus Accumbens) - positie symptoms

• Mesocortical pathway dysfunction (VTA to cortex) - Negative and cognitive sympotoms

Negative Symptoms in Schizophrenia

•affective flattening

•asociality

•anhedonia

•avolition

•lack of motivation to do or complete a task

•alogia

•reduced speech, even when encouraged to interact

Positive Symptoms in Schizophrenia

•hallucinations - false sensory perceptions

•auditory

•visual

•delusions - false beliefs about reality with no factual basis

•persecutory

•grandiose

•erotomania

•of control

1st Gen Antipsychotics

•D2 antagonists: haloperidol

•Anti-HAM

•histamine 1: weight gain, sedation

•Alpha 1: hypotension

•mACh: dry mouth, constipation, blurred vision

• gradual onset in effectiveness

Antipsychotic medications: other side effects

•Extrapyramidal symptoms:

•sedation

•Restlessness and pacing

•dystonia

•eye muscles pulls the eyes up

•Parkinsonism

•muscular rigidity, tremor, slow movements

•tardive dyskinesia

•uncontrollable movements of the lips, mouth, tongue

•Hyperprolactinemia

•Lactation and sexual dysfunction

Atypical Antipsychotics

•risperidone

•reduced EPS

•still anti-HAM

•weight gain even bigger

•hyperprolactinemia