Flashcards in Genetics, Anatomy, and Biochemistry of Behavior Deck (96):
Bipolar disorder and major depressive disorder recently have been associated with markers on chr. ...?
Chromosomal disorders with behavioral manifestations - Alzheimer?
Chr. 1 --> Depression, anxiety, dementia (early onset).
Chromosomal disorders with behavioral manifestations - Huntington:
Chr. 4 --> Erratic behavior, psychiatric symptoms (eg depression, psychosis), dementia.
Chromosomal disorders with behavioral manifestations - Sotos syndrome?
Chr. 5 --> Intellectual impairment, phobias, hyperphagia.
Chromosomal disorders with behavioral manifestations - William syndrome:
Chr. 7 --> Hypersociality, mental retardation, behavioral problems, hypotonia.
Chromosomal disorders with behavioral manifestations - Cohen syndrome:
Chr. 8 --> Autistic behavior, mental retardation.
Chromosomal disorders with behavioral manifestations - Dystonia musculorum deformans (DYT1), TS?
Chr. 9 --> Depression, learning problems, seizures, cognitive impairment, autistic behavior.
Chromosomal disorders with behavioral manifestations - AIP:
Chr. 11 --> Manic behavior, psychosis.
Chromosomal disorders with behavioral manifestations - PKU:
Chr. 12 --> ADHD, mental retardation.
Chromosomal disorders with behavioral manifestations - Wilson:
Chr. 13 --> Depression, personality changes, psychotic symptoms.
Chromosomal disorders with behavioral manifestations - Chromosome 15 inversion-duplication syndrome, Prader-Willi/Angelman syndrome:
1. Chr.15 inv-duplication syndrome --> Seizures, autistic behavior, hypotonia.
2. Prader-Willi/Angelman --> Mental retardation, rage, stubbornness, rigid thinking, and self-injury.
Chromosomal disorders with behavioral manifestations - Tuberous sclerosis:
Chr.16 --> Seizures, cognitive impairment, autistic behavior.
Chromosomal disorders with behavioral manifestations - NF-1, CMT disease, Smith-Magenis syndrome:
1. NF-1 --> Congitive impairment.
2. CMT disease --> Peripheral neuropathy.
3. Smith-Magenis syndrome --> Mental retardation, impaired expressive language, stereotyped behavior, clinging and dependency, seizures.
Chromosomal disorders with behavioral manifestations - Tourette syndrome:
Chr. 18 --> Dyscontrol of language and movements.
Chromosomal disorders with behavioral manifestations - Alzheimer (site of APO E4 gene):
Chr. 19 --> Depression, anxiety, dementia (typical age of onset).
Chromosomal disorders with behavioral manifestations - Progressive myoclonic epilepsy, AD (associated with Down syndrome):
1. Progressive myoclonic epilepsy --> Cognitive regression, aphasia, mental retardation.
2. Alzheimer (associated with Down syndrome) --> Depression, anxiety, dementia (early onset).
Chromosomal disorders with behavioral manifestations - Metachromatic leukodystrophy, NF-2, DiGeorge/velocardiofacial syndrome:
1. Metachromatic leukodystrophy --> Personality changes, psychosis, dementia.
2. NF-2 --> Hearing impairment.
3. DiGeorge/Velocardiofacial syndrome --> Schizophrenia, bipolar disorder, psychomotor retardation, language delay, ADHD, seizures.
Chromosomal disorders with behavioral manifestations - Fragile X syndrome, Kallmann syndrome, Lesch-Nyhan syndrome, Rett disorder:
1. Fragile X --> Autistic behavior, mental retardation.
2. Kallmann --> Anosmia, lack of sex drive, depression, anxiety, fatigue, insomnia.
3. Lesch-Nyhan --> Self-mutilation and other bizzare behavior, mental retardation.
4. Rett disorder --> Autistic behavior, hand-wringing, breathing abnormalities.
Studies for examining the genetics of behavior:
1. Family risk studies.
2. Twin studies.
Family risk studies:
Compare how frequently a behavioral disorder or trait occurs in the relatives of the affected individual (proband) with how frequently it occurs in the general population.
Adoption studies using monozygotic twins or dizygotic twins reared in the same or in different homes are used to differentiate the effects of genetic factors from environmental factors in the occurrence of psychiatric, substance abuse (eg alcoholism), and neuropsychiatric disorders.
Behavioral neuroanatomy - The cerebral hemispheres are connected by:
1. The corpus callosum.
2. Anterior commissure.
3. Hippocampal commissure.
4. Habenular commissure.
Sex differences in cerebral lateralization:
1. Women may have a larger corpus callosum + anterior commissure and appear to have better interhemispheric communication than men.
2. Men may have better-developed right hemispheres and appear to be more adept at spatial tasks than women.
Neuropsychiatric effects of brain lesions on behavior - Frontal lobes:
1. Mood changes (eg depression with dominant lesions/ mood elevation with nondominant).
2. Difficulties with motivation, concentration, attention, orientation, and problem solving (dorsolateral convexity lesions).
3. Difficulties with judgement, inhibitors, emotions, personality changes (orbitofrontal cortex lesions).
4. Inability to speak fluently (ie Broca aphasia [dominant lesions].
Neuropsychiatric effects of brain lesions on behavior - Temporal lobes:
1. Impaired memory.
2. Psychomotor seizures.
3. Changes in aggressive behavior.
4. Inability to understand language (ie Wernicke aphasia [dominant lesions]).
Neuropsychiatric effects of brain lesions on behavior - Limbic lobes, hippocampus, amygdala:
1. Poor new learning; implicated specifically in Alzheimer disease.
2. Kluver-Bucy syndrome (decr. aggression, incr. sexual behavior, hyperorality).
3. Decr. conditioned fear response.
4. Problems recognizing the meaningfulness of facial and vocal expression of anger in others.
Neuropsychiatric effects of brain lesions on behavior - Parietal lobes:
1. Impaired processing of visual-spatial information (eg cannot copy a simple line drawing or neglects the numbers on the left side when drawing a clock face [right-sided lesions]).
2. Impaired processing of verbal information (eg cannot tell left from right, do simple math, name fingers, or write [Gerstmann syndrome; dominant lesions]).
Neuropsychiatric effects of brain lesions on behavior - Occipital lobes:
1. Visual hallucinations and illusions.
2. Inability to identify camouflaged objects.
Neuropsychiatric effects of brain lesions on behavior - Hypothalamus:
1. Hunger leading to obesity (ventromedial nucleus damage).
2. Loss of appetite leading to weight loss (lateral nucleus damage).
3. Effects on sexual activity and body temp regulation.
Neuropsychiatric effects of brain lesions on behavior - Reticular system:
1. Changes in sleep-wake mechanisms (eg decr. REM sleep).
2. Loss of consciousness.
Neuropsychiatric effects of brain lesions on behavior - Basal ganglia:
Disorders of movement:
1. PD [substantia nigra].
2. HD [caudate and putamen].
3. Tourette syndrome [caudate].
1. Explicit or declarative memory involves the knowledge of facts and is retrieved CONSCIOUSLY.
2. Implicit or nondeclarative memory involves information on how to perform an act and is recalled UNCONSCIOUSLY.
Memory systems and associated neuroanatomy - Declarative (explicit or conscious) - 2 types:
Declarative (explicit or conscious) - Episodic - Associated anatomy:
1. Temporal lobes (medial).
2. Anterior thalamic nuclei.
5. Mammillary bodies.
6. Prefrontal cortex.
7. Inferolateral temporal lobes.
Declarative (explicit or conscious) memory - Semantic - Associated anatomy:
Inferolateral temporal lobes.
Declarative (explicit or conscious) memory - Length of recall:
Declarative (explicit or conscious) - Episodic used to remember:
Personally experienced events, eg what you ate yesterday.
Declarative (explicit or conscious) memory - Semantic - Memory used to remember:
General knowledge about the world, eg the capital of New Jersey.
Non declarative (implicit or unconscious) - 2 types:
Non-declarative (implicit or unconscious) - Procedural - Associated anatomy:
Cerebellum, basal ganglia, supplementary motor area.
Non-declarative (implicit or unconscious) - Working - Associated anatomy:
1. Prefrontal cortex.
2. Language and visual-association areas.
Non-declarative (implicit or unconscious) memory - Procedural or working is long term?
Give an example of procedural memory:
Things you do automatically, eg how you tie your shoes.
Non-declarative (implicit or unconscious) memory - Give an example of working memory:
Recent information, eg the phone number just obtained from "information".
Neurotransmitters are excitatory if ...?
They increase the chances that a neuron will fire.
Neurotransmitters are inhibitory if ...?
They decrease the chances of neuronal firing.
What is neuronal plasticity?
The changeability of number or affinity of receptors for specific neurotransmitters --> can regulate the responsiveness of neurons.
Classification of neurotransmitters - 3 major classes of neurotransmitters:
1. Biogenic amines (monoamines).
2. Amino acids.
Psychiatric conditions and associated neurotransmitter acivity - Depression:
NE (-), Serotonin (-), Dopamine (-).
Psychiatric conditions and associated neurotransmitter activity - Mania:
Dopamine (+), GABA (-).
Psychiatric conditions and associated neurotransmitter activity - Schizophrenia:
Dopamine (+), Serotonin (+), Glutamate (+/-).
Psychiatric conditions and associated neurotransmitter activity - Anxiety:
GABA (-), Serotonin (-), NE (+).
Psychiatric conditions and associated neurotransmitter activity - Alzheimer:
ACh (-), Glutamate (+).
The biogenic amines, or monoamines, include:
3. Ethyl amines.
4. Quaternary amines.
Metabolites of monoamines and associated psychopathology - Dopamine - Incr. HVA - Associated psychopathology:
Schizophrenia and other conditions involving psychosis.
Metabolites of monoamines and associated psychopathology - Dopamine - Decr. HVA - Associated psychopathology:
2. Treatment with antipsychotic agents.
Metabolites of monoamines and associated psychopathology - NE - Incr. VMA - Associated psychopathology:
Adrenal medulla tumor (pheochromocytoma).
Metabolites of monoamines and associated psychopathology - NE - Decr. MHPG - Associated psychopathology:
Severe depression and attempted suicide.
Metabolites of monoamines and associated psychopathology - Serotonin - Decr. 5-HIAA - Associated psychopathology:
1. Severe depression.
2. Attempted suicide.
3. Aggressiveness and violence.
5. Tourette syndrome.
6. Alcohol abuse.
Dopamine, a catecholamine, is involved in the pathophysiology of:
1. Schizophrenia + other psychotic disorders.
3. Mood disorders.
4. The conditioned fear response.
5. The "rewarding" nature of drugs of abuse.
The amino acid tyrosine is converted to the precursor for dopamine by the enzyme TYROSINE HYDROXYLASE.
Dopamine - Receptor subtypes:
D1-D5 have been identified; the major site of action is D2 for traditional antipsychotic agents and D1 and D4 as well as D2 for the NEWER "atypical" antipsychotic agents.
The nigrostriatal tract is involved in the regulation of ...?
1. Muscle tone.
Dopamine acts on the TUBEROINFUNDIBULAR tract to inhibit ...?
The secretion of prolactin from the anterior pituitary.
Which tract is associated with psychotic disorders?
The mesolimbic-mesocortical tract.
The mesolimbic-mesocortical tract may have a role in ...?
The expression of emotions since it projects into the limbic system and prefrontal cortex.
Hyperactivity and hypoactivity of the mesolimbic tract:
Hyperactivity --> Positive symptoms (Eg hallucinations).
Hypoactivity --> Negative symptoms (eg apathy) of schizophrenia.
NE is a catecholamine plays a role in ...?
Besides dopaminergic neurons, which other neurons synthesize dopamine?
Which enzyme converts the dopamine synthesized in noradrenergic neurons to NE?
Most noradrenergic neurons (approx. 10.000 per hemisphere in the brain) are located in the ...?
Serotonin, an indolamine, plays a role in ...?
4. Impulse control.
Elevation of serotonin is associated with ...?
Improved mood + decr. sexual function (particularly delayed orgasm).
Very high levels of serotonin are associated with ...?
Decr. serotonin is associated with ...?
1. Poor impulse control.
3. Poor sleep.
The aminoacid tryptophan is converted to serotonin (also known as 5-hydroxytryptamine) by the enzyme TRYPTOPHAN HYDROXYLASE as well as by an AA DECARBOXYLASE.
Serotonin - Localization:
Most serotonergic cell bodies in the brain are contained in the DORSAL RAPHE NUCLEUS in the upper pons + lower midbrain.
Antidepressants and serotonin:
1. Heterocyclic antidepressants (HCAs).
Histamine, an ethylamine, is affected by ... drugs.
Histamine receptor blockade with drugs such as antipsychotics and TCAs is associated with ...?
Common side effects of these drugs such as sedation + incr. appetite leading to weight gain.
Degeneration of CHOLINERGIC neurons is associated with ...?
3. Movement and sleep disorders (decr. REM cycle).
Cholinergic neurons synthesize ACh from ...?
Acetyl CoA and choline using the enzyme choline acetyltransferase.
Which brain area is involved in the production of ACh?
The nucleus basalis of Meynert.
Glutamate is an excitatory neurotransmitter that contributes to the pathophysiology of:
Neurodegenerative illnesses such as:
The mechanism of the association of glutamate with neurodegenerative illnesses involves?
Activation of the glutamate receptor N-methyl-d-aspartate (NMDA) by sustained elevation of glutamate.
Sustained NMDA receptor activation results in ...?
Calcium ions entering neurons leading to nerve cell degeneration and death through excitotoxicity.
Memantine (Namenda) is an ...?
NMDA receptor antagonist.
Role of memantine:
Ultimately blocks this influx of calcium and is indicated for patients with moderate to severe AD.
GABA is the principal inhibitory neurotransmitter in the CNS. It is synthesized from ...?
Glutamate by the enzyme GLUTAMIC ACID DECARBOXYLASE, which needs B6 as a cofactor.
GABA is closely involved in the action of ...?
Anti-anxiety agents such as benzodiazepines + barbs.
Glycine is an inhibitory neurotransmitter found primarily in ...?
The spinal cord.
Glycine works on its own and as a regulator of ...?
Endogenous opioids such as enkephalins, endorphins, dynorphins, and endomorphins are produced by the brain itself. They act to ...?
Decr. pain + anxiety and have a role in ADDICTION + MOOD.
Placebo effects may be mediated by the endogenous opioid system. For example, prior treatment with an opioid receptor blocker such as naloxone can do what to placebo effects?
BLOCK THE PLACEBO EFFECTS.