Psychopharmacology

Complex 1.4 kg in weight Pre frontal cortex 2% of body weight 20% of oxygen 15% of our cardiac input 10% of all energy

Brain protection system The BBB is both;

A physical barrier that restricts the entrance of potentially harmful substances

A system of cellular transport mechanisms that controls the entrance of essential nutrients

Cerebrum and Cerebral cortex Left and Right Hemispheres Left Hemisphere- dominant hemisphere

Production of language Mathematical ability Problem solving

•Right Hemisphere - Creativity

- Spatial ability

Located at the front of both cerebral hemispheres

Primary motor cortex Pre motor cortex Broca’s Area Complex Functioning – personality,

judgement, insight, reasoning, problem solving, abstract thinking and working memory

Located behind frontal lobe Somatosensory cortex Spatial orientation, perception and

comprehension of language function recognising objects by touch

Links visual and somatosensory information together

Neglect

Located et each side of the brain Involved in receiving and processing

auditory information, higher order visual information , complex aspects of memory and language

Wernicke’s area

Visual processing area

Corpus Callosum

• Thalamus• Filter for sensory

information• Control of mood

states• Body movement

• Hypothalamus• Central control• Regulate

autonomic, emotional, endocrine and somatic function

• Stress

Cerebellum Equilibrium Muscle tone Postural control Coordination of muscle movement

Pons Relay station

• Medulla Oblongata• Skeletal muscles• Balance• Coordination• Inner ear sound

impulses• Heart rate, vomiting,

sneezing• Reticular formation

• Arousal• Circadian rhythm• respiration

Basal ganglia Muslce tone Posture Movement

Substantia Nigra

Amygdala Mood

Hippocampus Memory

The structural unit of the brain Cell body Axon Dendrites Synapse

• The Information that flows in the neurone• Approximately 10 billion neurons are responsible

for receiving, organising and transmitting information in the central nervous system

• Ions in the intracellular fluid (inside the cell) have a negative charge

• Ions in extracellular fluid (outside the cell) have a positive charge attracting positively charged cells (cations)

• ‘Potential difference’ between the inside and the outside of the cell

•

Ions are sodium, potassium, calcium and chloride

‘voltage gated’ Resting Potential vs. Action potential

The flow of neurotransmitter across the synapse

Neurotransmitter; Made in the pre synaptic neurone Stored inactively in synaptic vesicles Released from the synaptic vesicles into the

synapse Binds to receptors Binds to reuptake transporters to be taken back

into the neurone Is degraded by specific enzymes

Acetylcholine (ACh) Norepinephrine (NE)( also known as

noradrenaline) Dopamine(D) Serotonin (5HT) Glutamate Gamma-aminobutyric acid (GABA)

There are two kinds of neurotransmitters – INHIBITORY and EXCITATORY.

stimulate the brain calm the brain

• Cholinergic pathways

• thought to be involved in cognition (esp. memory) and our sleep/wake cycle

• parasympathetic nervous system regulating bodily functions such as heart rate, digestion, secretion of saliva and bladder function

• Alzheimer’s disease and myathesia gravis (weakness of skeletal muscles)

• Anti-cholinergic effects

• attention, alertness and arousal

• NE levels fluctuate with sleep and wakefulness and changes in attention and vigilance

• mood, affective states and anxiety

• antidepressant

• complex movement and cognition

• Emotional responses such as euphoria or pleasure (seen in amphetamine/cocaine use).

•Significant role in motor control

•EPSE’s

• Great influences on behaviour.

• Low serotonin activity is associated with aggression, suicide, impulsive eating and dis-inhibited sexual behaviour

• modulating general activity levels of the CNS, particularly the onset of sleep

• depression and anxiety disorders

• delusions, hallucinations (LSD)

• negative symptoms of schizophrenia

Glutamate is found in all cells of the body control the opening of ion channels that

allow calcium to pass into nerve cells producing impulses

Blocking of glutamate receptors produces ( eg. By PCP) schizophrenic like symptoms

Over exposure of neurons to glutamate cause cell death seen in stroke and Huntington’s disease (PN).

Inhibitory and its pathways are only found within the CNS.

control excitatory neurotransmitters in the brain and controlling spinal and cerebral reflexes.

anxiety disorders decreased GABA can lead to seizure

activity Benzodiazepines and barbiturates

sedative medication act on GABA