An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome.
i.e. eye color... Bb BB bb bB
Autosomes vs. sex chromosomes
Twenty-two of these chromosome pairs are called autosomes, and the two in each pair are alike in that they have the same kinds ofgenes in the same places. The remaining pair are called sex chromosomes.
problem with a chunk of chromosomal material (rather than just a defective code in a single gene)
Neurotransmitter whose generalized finction is to activate other nt's and to aid in exploratory and pleasure-seeking behaviors.
Gene disorders refer to alleles on particular genes that contain defective codes.
Frontal, temporal, parietal, and occipital lobes
Frontal: At the front of the brain, behind the forehead. The frontal lobes play an executive role in the brain, regulating complex activities, organizing the person for action, carrying out speech and motor movements, and moderating emotion.
- Temporal: At the sides, along the temples. The temporal lobes are important in memory, receiving and organizing auditory input, and helping to
- integrate and provide sensory input to the brain's emotional centers. Epilepsy due to lesions of the temporal lobes often manifests with
- psychiatric symptoms.
- Parietal: At the top-middle to top-back. The parietal lobe is responsible for the sensation of touch. It has important functions for integrating diverse sensory input, translating vision, hearing, touch, and memory into meaningful experiences.
- Occipital: At the back of the brain. The occipital lobes are largely responsible for receiving and organizing visual information, perhaps the most
- sophisticated sense in humans.
- Generally, the left hemisphere is specialized for language and for processing information in a logical, sequential order. It also tends to receive sensory input from and control output to the right side of the body. The right hemisphere is typically specialized for spatial, simultaneous
- processing, such as that used in mechanical tasks or in appreciation of art and music, and for input from and output to the left side of the
Part of the forebrain involved in emotion, the ability to learn and control impulses and the regulation of sex, hunger, thirst and aggression.
This principle posits that the brain is an organized entity that acts in concert. Damage to one area may particularly affect one brain function, but it may also have consequences for a host of end-point behaviors. John Hughlings Jackson.
Drug that blocks dopamine receptor sites. Used to treat Schizophrenia.
Disorders caused by multiple genes.
Primary, secondary, and tertiary centers
Primary centers receive sensory input and perform basic organization. Secondary centers further organize the information into meaningful components. Tertiary centers integrate sensory information from different senses and from memory into the experience of perception.
Receptive vs. expressive
Receptive brain includes the areas forreceiving and organizing audition, touch, and vision, with importantpathways to the lower centers of taste and smell. Expressive brain includes motor and speech centers, as well as brain centers allowing for meaningful use of motivating emotions.
Reptilian, paleomammalian, and neomammalian brain
Lower, interior brain structures, mostly part of the brain stem, form the reptilian brain. The name derives from the similarity of these structures to those in primitive animals. These structures are primarily responsible for basic bodily mechanisms, such as heart rate, and for control of instinctual urges, such as feeding. The second level of structures is the paleomammalian brain, composed of structures largely shared with early mammals. In the human, many of these structures form a system referred to as the limbic system. These structures help us respond more readily to our environment (e.g., warm-blooded) and are responsible for basic emotional responses, such as fear. The third level of structures is the neomammalian brain, consisting of the cortex which covers most of the lower centers. This we share primarily with other primates, although the human cortex is substantially more sophisticated. The cortex allows for complex thought and memory formation, and substantial control over ourselves (for example, we can in many ways "control" our emotions).
NT involved in processing information and coordination of movement as well as inhibition and restraint; it also assists in the regulation of eating, sexual and aggressive behaviors, all of which may be involved in different psychological disorders. It's interaction with dopamine is implicated in schizophrenia.
Serotonin selective reuptake inhibitors. Drugs that inhibit the reuptake of serotonin.
Studies of heritability: family, twin, adoption
- Family study: If a condition is genetic, we expect that affected persons will have a greater proportion of affected first-degree relatives than
- second-degree relatives, and that proportions for relatives will be greater than the prevalence of the condition in the general population.
we take advantage of the genetic difference between identical twins(with 100% of genes in common) and non-identical twins (who share the same proportion of genes as other siblings—about 50%). If identical twins have greater concordance than fraternal twins, we are much more confident that the condition has genetic causes because both kinds of twin pairs share the same family environment.
Natural patterns of adoption give us a chance to see if those with shared genes (e.g., children, siblings, or even twins) who are raised apart are at higher concordance as compared to the general population.
Group of anti-depressents that inhibit the reuptake of both serotonin and norepinephrine, but mostly the latter.
Sex chromosome disorders
Turner's Syndrome: The second sex chromosome is missing (denoted "X0"). (Note that without at least one X chromosome the organism is not viable; therefore there is no Y0.) The phenotype is a female, usually short with webbed neck and shield-like chest, usually sterile or sexually immature, and spatial difficulties are common.
Kleinfelter's Syndrome: There is an extra X chromosome (female XXX or male XXY). These individuals tend to be tall, sometimes with underdeveloped sex organs. They are over-represented in correctional institutions, although the reasons are unclear.
XYY: There is an extra Y chromosome. These males tend to be tall, with acne, abnormal EEGs, and lower IQs. They are over-represented in prisons (this was previously thought to be because they were overly aggressive, but more recent research does not support this idea).
Down's Syndrome (Trisomy 21): This results from an extra chromosome 21 or from an extra fragment. The phenotype can typically include moderate to severe mental retardation, structural heart abnormalities, short stature, mild temperament, and webbing of the neck, fingers and toes.
Dominant Gene Inheritance disorders
Huntington's Chorea: This disorder is always fatal, but is maintained in the gene pool because it is not expressed until middle age, after the chance of passing the defective gene to one's children. Essentially, the disorder results initially in loss of motor control (chorea refers to the jerky movements of its victims), followed by progressive deterioration of the central nervous system.
Bipolar Disorder (Manic-Depressive Illness): The high concordance rates for bipolar disorder suggest it too may be a dominant (or single) gene disorder.
Recessive Gene Inheritance
Phenylkentonuria (PKU): An incorrect recipefor an enzyme results in ketones (contained in certain food) not being metabolized, thereby building up to toxic levels in the brain. Although the problem is genetic, the current treatment is environmental—simply don't eat foods containing ketones. By controlling diet, the worst part of the traditional phenotypic outcome—mental retardation—is avoided.