1. NEUROBIOLOGICAL Implications of Psychiatric Illnesses
Dr. Ali Al-Juboori
Assist. Professor

2. Anatomy and Physiology Review

3. Cerebrum
Right and left hemispheres connected by the corpus callosum

4. Lobes of the Cerebrum

5. Frontal Lobe Controls
• Movement • Thinking initiation • Reasoning (judgement) • Behavior (emotions) • Memory • Speaking

6. • Knowing right from left • Sensation • Reading • Understanding
Parietal Lobe Controls
• Knowing right from left • Sensation • Reading • Understanding

7. Temporal Lobe Controls
• Understanding language • Behavior • Memory • Hearing

8. Occipital Lobe Controls
• Vision • Color blindness
Cerebellum Controls
• Balance • Coordination • Fine muscle control

9. Brain Stem Controls
• Breathing • Blood pressure • Heartbeat • Swallowing • Alertness/sleep • Body temperature • Digestion

10. Consists of many structures
Limbic System
“The Emotional Brain:”
Consists of many structures
Functions include Memory, Pleasure, Emotions, Motivation

12. Functions of The Limbic System

13. More Functions of Limbic System
Olfactory Functions
Feeding Functions
(consider the relationships between emotions, pleasure, smell, and food intake!)

14. Some Important Structures Connecting to the Limbic System
Hypothalamus-activates & controls many body functions: endocrine, sleep, appetite, body temp.
Pineal Gland- role in sleep (secretes melatonin) and consciousness

15. Important Structures Connecting to Limbic System, cont’d
Thalamus-association of sensory inputs with pleasant and unpleasant feelings
Hippocampus-memory processing, and making of new memories
Amygdala-stores feelings relating to memories,

16. Autonomic Nervous System
Sympathetic: Dominates in stressful situations, prepares body for fight or flight
Parasympathic: Dominates when person is relaxed

17. Neurons: A Review Nerve Tissue CNS: neurons, composed of:
Cell body contains nucleus (genetic material)
Axon transmits message to next cell
Dendrites receive messages from cell

19. Three classes of neurons in CNS
Afferent (sensory)
Efferent (motor)
Interneurons

20. Synapse: the contact point between two neurons.
Synaptic Cleft: space between neurons
Pre-synaptic neuron: area of axon where neurotransmitters are stored.
Postsynaptic neuron: area of dendrite where receptor sites are located.

21. Neurotransmission =
Chemical Signalling

22. Neurotransmission (Physiology)
Neurotransmitters are released into the synaptic cleft (space) from the axon to the dendrite.
(--Calcium ions facilitate NT release)
NTs bind with receptors on post-synaptic neuron (dendrite) and activate it
Then NT substance is either deactivated or returned to the axon (“reuptake”).
Nerve cells can release more than one type of neurotransmitter

23. Pre-synaptic and postsynaptic
neuron interchange

24. Neurotransmission Across the Synapse

25. Role of Neurotransmitters in Mental Health
Play an important role in human emotions and behavior
Influence motor activity and hormone levels
Are the target for the mechanism of action for psychotropic medications

26. Categories of Neurotransmitters
1.Cholinergics
Acetylcholine (ACh): involved in sleep, arousal, movement, memory

27. 2.MONOAMINES
Norepinephrine: affects mood, cognition, perception, locomotion, sleep and arousal
Dopamine: effects movement, coordination, emotions, voluntary judgment, and release of prolactin

28. 3.Amino Acids
Gamma Aminobutyric Acid (GABA) functions as an inhibitory neurotransmitter (“brain calmer”)
Glutamate excitatory

29. 4. Neuropeptides: endorphins and enkephlins, modulate pain
4.Neuropeptides: endorphins and enkephlins, modulate pain. Also called “natural or endogenous opiates”

30. Neurobiology and Mental Illness
Neuroanatomical Changes (examples)
-Enlargement of ventricles: schizophrenia, alcoholism -Atrophy of hippocampus: trauma or severe stress in early life

31. Decreased Cerebral Blood Flow -In Prefrontal cortex: Schizophrenia
(Some examples:)
-In Prefrontal cortex: Schizophrenia
-In Frontal lobe: Attention-Deficit Hyperactivity Disorder (ADHD)

32. Neurotransmitter Dysfunction
Lack of availability or lack of secretion
(Some examples:)
Too much dopamine: Schizophrenia
Insufficient serotonin: Depression
Insufficient norepinephrine: Depression
Insufficient GABA: Anxiety disorders
Too much norepinephrine: Anxiety Disorders

33. Dopamine: Excessive transmission in limbic structures may contribute to schizophrenia.
5-HT: Ascending projections control mood; increase appears to help in many forms of anxiety and depression (mood disorders).
Norepinephrine: Excessive transmission may contribute to anxiety and aggression. Under-reaction, along with that of 5-HT, may contribute to depression.
Acetylcholine: Important in cognition, activating a limbic areas to degenerate in Alzheimer’s Disease.

34. Neuroendocrine Dysfunction
(examples)
-Altered Hypothalamic regulatory mechanisms: Anorexia Nervosa
-Increased Hypothalamic-Pituitary-Adrenal Axis (HPA) activity causing elevated cortisol (stress hormone) levels: Caused by early life deprivation, trauma or stress
-Thyroid dysfunction: (Hyper-)Anxiety, (Hypo-) Depression

35. Thanks