Genetics and Biochemistry of Behavior

GENETICS, GENETICS, NEUROANATOMY NEUROANATOMY

AND AND BIOCHEMISTRY OF BIOCHEMISTRY OF

BEHAVIORBEHAVIOR

Describe family, twin and adoption Describe family, twin and adoption studiesstudies

Describe brain and behavior relationshipDescribe brain and behavior relationship Describe the role of central and peripheral Describe the role of central and peripheral

nervous system in behaviornervous system in behavior Describe the role of important Describe the role of important

neurotransmitters in behaviorneurotransmitters in behavior

The study of Genetics involves:The study of Genetics involves:

11..  Family studiesFamily studies 2. 2. Twin studies Twin studies 3. 3. Adoption studiesAdoption studies

The study of Genetics involves:The study of Genetics involves:

11..  Family studiesFamily studies 2. 2. Twin studies Twin studies 3. 3. Adoption studiesAdoption studies

FAMILY STUDIESFAMILY STUDIESLifetime expectancy of Lifetime expectancy of

schizophrenia in the relatives of schizophrenia in the relatives of schizophrenicschizophrenic

RelationshipRelationship Percentage% Percentage% SchizophrenicSchizophrenic

Parent Parent 5.6 5.6 Sibling 10.1Sibling 10.1 Sibling (when one parent also affected) 16.7Sibling (when one parent also affected) 16.7

ChildrenChildren 12.8 12.8 Children (both parents affected) Children (both parents affected) 46.3 46.3

Uncles/aunts/nephews/niecesUncles/aunts/nephews/nieces 2.8 2.8Grand children Grand children 3.7 3.7

UnrelatedUnrelated 0.86 0.86

TWIN STUDIESTWIN STUDIES Probandwise concordance in schizophrenia twin Probandwise concordance in schizophrenia twin

studies (after Gottesman & shields 1976)studies (after Gottesman & shields 1976)MZ pairs DZ pairs MZ pairs DZ pairs

n Concordance(%)n Concordance(%) n n Concordance(%)Concordance(%)

   Kringlen (1967) Kringlen (1967) 5555 45 45 90 90 15 15 Pollin et al (1969)Pollin et al (1969) 9595 43 43 125 125 9 9 Tienari (1968)Tienari (1968) 1616 35 35 21 21 13 13 Fischer (1973)Fischer (1973) 2121 56 56 4141 26 26 Gottesman & Gottesman & Shields (1972) 22 58 33Shields (1972) 22 58 33 12 12

ADOPTION STUDIESADOPTION STUDIES

These studies are aimed at These studies are aimed at separating genetic and environmental separating genetic and environmental influences for particular traits in influences for particular traits in children adopted away from their children adopted away from their biological parents and raised by biological parents and raised by unrelated adoption parents.unrelated adoption parents.

BRAIN & BEHAVIOUR-BRAIN & BEHAVIOUR-RELATIOSHIPRELATIOSHIP

Human nervous system consists of:Human nervous system consists of:

1. Central nervous system1. Central nervous system 2. Peripheral nervous system2. Peripheral nervous system

Central nervous system includes Brain Central nervous system includes Brain and Spinal cord.and Spinal cord.

The peripheral nervous system The peripheral nervous system consists of:consists of:

1. 1. Cranial nerves Cranial nerves 2. Spinal nerves2. Spinal nerves3. Autonomic ganglia and plexes3. Autonomic ganglia and plexes

Central Sulcus

The brain is divided into:The brain is divided into:   i.i.  Two cerebral hemispheresTwo cerebral hemispheres  ii.ii.  AnatomicallyAnatomically into four lobes i.e., into four lobes i.e.,

frontal, temporal, parietal and frontal, temporal, parietal and occipital lobe occipital lobe iii. iii. HistologicallyHistologically in various neuronal in various neuronal

layers layers FunctionallyFunctionally into motor, sensory, other into motor, sensory, other

specific and association areasspecific and association areas

CEREBRAL HEMISPHERESCEREBRAL HEMISPHERES

a)a) The hemispheres are connected by The hemispheres are connected by the corpus callosum, anterior the corpus callosum, anterior commissure, hippocampal commissure commissure, hippocampal commissure and hebenular commissure.and hebenular commissure.

Q.Q. Which of the following two Which of the following two structural entities connect the structural entities connect the cerebral hemispheres?cerebral hemispheres?

a.a. Basal ganglia and anterior Basal ganglia and anterior commissurecommissure

b.b. Anterior commissure and reticular Anterior commissure and reticular systemsystem

c.c. Reticular system and corpus callosum Reticular system and corpus callosumd.d. Amygdala and habenular commissure Amygdala and habenular commissure

b) The functions of the hemisphere b) The functions of the hemisphere are lateralized.are lateralized.

                        i.i.  The right or non dominant The right or non dominant hemisphere is associated primarily hemisphere is associated primarily with:with:

PERCEPTIONPERCEPTION SPATIAL RELATIONSSPATIAL RELATIONS BODY IMAGEBODY IMAGE ARTISTIC ABILLITYARTISTIC ABILLITY

Q.Q. A 65 years old female patient has had A 65 years old female patient has had a stroke affecting the left hemisphere a stroke affecting the left hemisphere of her brain. Which of the following of her brain. Which of the following functions is most likely to be affected functions is most likely to be affected by the stroke?by the stroke?

a.a. Perception Perceptionb.b. Musical ability Musical abilityc.c. Spatial relations Spatial relationsd.d. Language Language e.e. Artistic ability Artistic ability

  ii.ii.  The Left or dominant hemisphere is The Left or dominant hemisphere is associated with language functions in associated with language functions in about 96 % of right handed people about 96 % of right handed people and 70 % of left handed people.and 70 % of left handed people.

Neuropsychiatric Effects of Neuropsychiatric Effects of Brain LesionsBrain Lesions

• Location Location of Lesionof LesionFrontal LobeFrontal LobeTemporal Temporal LobeLobeParietal LobeParietal LobeOccipital LobeOccipital LobeLimbic Limbic SystemSystemHypothalamuHypothalamuss

• Effects of LesionEffects of Lesion

HYPOTHALAMUS AND HYPOTHALAMUS AND PITUITARYPITUITARY

Hypothalamus and pituitary are involved Hypothalamus and pituitary are involved in the regulation of:in the regulation of:

i.i. SleepSleepii.ii. Appetite Appetiteiii.iii. Sexual activity Sexual activity

iv.iv. Major endocrine regulation of Major endocrine regulation of the bodythe body

v.v. Body immune system Body immune systemvi.vi. Autonomic nervous system of Autonomic nervous system of

the body.the body.

BIOCHEMISTRY OF BIOCHEMISTRY OF BEHAVIORBEHAVIOR

Neurotransmission across synapses Neurotransmission across synapses (contact between neurons) is carried (contact between neurons) is carried out through the release of chemical out through the release of chemical substances called neurotransmitters. substances called neurotransmitters.

Neurotransmitters can be:Neurotransmitters can be: a.a. Biogenic aminesBiogenic amines b. Amino acidsb. Amino acids c. Peptidesc. Peptides

MOVIEMOVIE

Biogenic amines include dopamine, Biogenic amines include dopamine, nor epinephrine, serotonin, histamine nor epinephrine, serotonin, histamine and acetylcholine.and acetylcholine.

Dopamine is involved in Dopamine is involved in Norepinephrine has a role in Norepinephrine has a role in Serotonin plays a role inSerotonin plays a role in Histamine is affected by Histamine is affected by Acetylcholine is mainly released at Acetylcholine is mainly released at

MT

Amino Acid Neurotransmitters Amino Acid Neurotransmitters are:are: Gamma amino butyric acid (GABA), Gamma amino butyric acid (GABA),

glyine and glutamateglyine and glutamate

NEUROPEPTIDESNEUROPEPTIDES Encephalins and endorphins are Encephalins and endorphins are

endogenously produced by brain and endogenously produced by brain and are involved in relief of pain and are involved in relief of pain and anxiety.anxiety.

Other Neuropeptides are implicated in Other Neuropeptides are implicated in schizophrenia, mood disorders, schizophrenia, mood disorders, Huntington’s chorea, dementia, Huntington’s chorea, dementia, anxiety disorders, pain conditions and anxiety disorders, pain conditions and aggression.aggression.

Q.Q. The major neurotransmitter The major neurotransmitter implicated in both Alzheimer implicated in both Alzheimer disease and schizophrenia isdisease and schizophrenia is

a. Serotonina. Serotoninb. Norepinephrineb. Norepinephrinec. Dopaminec. Dopamined. Acetylcholined. Acetylcholinee. Gamma-aminobutyric acid (GABA)e. Gamma-aminobutyric acid (GABA)f. Glutamatef. Glutamate