Lecture 15 Outline of Last Lecture I. Pharmacokinetics involves the movement of drugs throughout the bodya. Various means drugs are absorbed into the blood and brainb. Distribution of drugs are limitedi. Certain molecules cannot pass through the blood-brain barrierc. A drug may be broken down into its components or stored in certain somatic cellsd. There are various means of eliminationII. Psychoactive drugs directly target the nervous systema. May target synapses, post-synaptic receptors, reuptake mechanisms, transmitter synthesis ratesIII. Drug responses are mediated by various meansa. Potencyb. Efficacyc. Variabilityd. Effective concentrations/dosagese. ToleranceOutline of Current Lecture I. Drugs’ effects may sum if absorbed by the body at the same timea. Produce IPSPs or EPSPsII. Dependency, sensitization, learning, and other variables such as basal metabolic rate and sex alter a drug’s effects on an individualIII. A neurohormone is any hormone produced and released by neuroendocrine/neurosecretory cells into the blooda. A feedback system referred to as the HPA axis is responsible for the stress response and includes a fast and slow-acting pathwayCurrent Lecture- Pharmacokinetics: determining the date of substances administered externally to a livingorganism- Tolerance is a reduced response to repeated exposure to a drug doseo Opioid analgesics: morphine, codeine, heroin, endomorphins, enkephlins, dynorphinso Cross-tolerance: barbiturates and alcohol GABA channels that are selective for chloride ions- Also contains receptors for ethanol, barbiturates, neurosteroids- Reduces the effectiveness of each other once exposedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. NSCI 110 1st Edition- Some factors that alter drug effectso Drug interactions Taking multiple drugs may drastically increase the magnitude of the effectby inducing EPSPs and IPSPso Dependency: requiring a drug to maintain a normal response Absence of the results in abstinence syndrome (withdrawal)- Physiological (heroin)- Psychological - Combination o Sensitization: increased responsiveness (intensity, type) to repeated exposure to a drug dose Increased receptor density (upregulation); binding affinity) Drug interactionso Learning: unexpected vs expected effects Monkeys and amphetamine- Drink fruit punch which activates sympathetic nervous system, butthey learn nothing harmful occurs- Second effect causes activity to be lower than baseline level Placebo effecto Subject variables Age Environment Sex Body weight Basal metabolic rate- Neurohormoneso A hormone is a chemical released by endocrine glands into the bloodstream to affect an organ at a distance A neurohormone is any hormone produced and released by neuroendocrine/neurosecretory cells into the bloodo Hypothalamus produces neurohormones that enter the anterior pituitary gland through veins and the posterior pituitary through axons in response to stimuli Through instructions from these released hormones, the pituitary sends hormones into the bloodstream to target endocrine glands Endocrine glands release their own hormones that stimulate target organs, including the brain This feedback system is known as the hypothalamus-pituitary-adrenal (HPA) axiso Steroid hormones (testosterone, cortisol) Synthesized from cholesterol and lipids Easily crosses cell membranes Often target DNAo Peptide hormones (insulin, growth hormones) Peptides made from DNA Bind to receptors (usually second messenger systems)- The HPA axis includes two pathwayso Fast-acting pathway: Hypothalamus sends message through the spinal cord Sympathetic division is activated to stimulate the medulla of the adrenal gland The adrenal medulla releases epinephrine into the circulatory system Epinephrine activates the body’s cells, endocrine glands, and the braino Slow-acting pathway: (mechanism for managing long-term stress) Hypothalamus releases CRH (corticotropin releasing hormone) into the pituitary gland The pituitary gland releases ACTH (adrenocorticotropic hormone), which acts on the cortex of the adrenal gland The adrenal cortex releases cortisol into the circulatory system Cortisol activates the body’s cells, endocrine glands, and the braino Homeostatic hormones maintain internal balance and regulate physiological systems Antidiuretic hormoneo Gonadal hormones control reproduction Estrogen, testosteroneo Glucocorticoids are involved in stress response Cortisol, corticosterone- Parvocellular neurosecretory cells and anterior