HOW DOES EXPERIENCE AFFECT BEHAVIOUR AND MENTAL PROCESSES? NERVOUS SYSTEM: INTERFERENCE

How interference to neurotransmitter function can affect nervous system functioning there is compelling research evidence that too little or too much of a specific neurotransmitter can have a significant impact on how we think, feel or behave because of its effect on nervous system functioning. PARKINSON’S DISEASE

PARKINSON’S DISEASE a CNS neurodegenerative disorder characterised by both motor and non- motor symptoms.

substantia nigra Degeneration here = motor loss Dopamine is produced here Therefore, amount of dopamine available for motor activity reduces as neurons die. Located in the midbrain – has a role in the control of voluntary muscle movements

DOPAMINE Carries messages on how to control body movements First to the basal ganglia Then to frontal lobes Fewer neurons = less dopamine = less messages about motor activity In this area!

PRIMARY MOTOR CORTEX Receives inadequate information Symptoms only appear after extensive neuronal death (at least 60% loss) Parkinson’s disease is not considered to be genetic though there is a family history of the disorder in about 15% of cases. The only real risk factor seems to be age

SYMPTOMS PARKINSON’S DISEASE The symptoms of Parkinson’s disease develop slowly and gradually progress over years. They tend to vary greatly between individuals diagnosed with the disorder and no two people will be affected in the same way. In addition, both motor and non-motor symptoms also tend to vary in severity from day to day and at different times throughout the day. - FOUR KEY SYMPTOMS PARKINSON’S DISEASE

TREMOR continuous, involuntary shaking (trembling) of the body 30% of people with the disease will not experience tremor. Most often, tremors are ‘resting tremors’ and occur when the affected limb is not in use regular and rhythmic, occurring at the rate of about 4–6 times per second. ‘Restless legs’: the person’s legs appear to move or feel as if they are moving constantly.

MUSCLE RIGIDITY muscles seem unable to relax and are tight, even when at rest muscles will not do what they want them to do may have difficulty performing automatic movements may feel their muscles are so tight that they have frozen

MUSCLE RIGIDITY can also lead to lack of facial expression through loss of facial muscle tone first occurs on one side of the body, then eventually progresses to both sides can lead to the characteristic stooped or ‘forward bent’ posture apparent in many people with the disorder

SLOWNESS OF VOLUNTARY MOVEMENT bradykinesia particularly when initiating and executing movement and in performing repetitive movements decrease in fine motor coordination required for ‘delicate’ work with the hands Presents in a variety of ways, including difficulty starting new movements or stopping an ongoing movement. also affects walking, talking, chewing, swallowing and speaking,

Postural instability, balance problems and gait (walking) disturbances Inability to maintain a steady, upright posture or to take a corrective action to prevent a fall Gait disturbance is apparent in the short, shuffling steps In advanced Parkinson’s disease, there may be episodes of freezing tend to occur later in the course of the disorder.

NON-MOTOR SYMPTOMS decrease or loss of sense of smell (called anosmia) sweating increased sensitivity to temperatures Fatigue mental health: confusion, panic attacks, anxiety disorder and depression Cognitive: slowness of thinking, impaired planning and decision making memory loss may occur in up to 40–50% of people tend to occur later in the course of the disorder.

CURE Currently no cure Medications can relieve symptoms by increasing dopamine 1 – converts into dopamine 2 – mimics the role of dopamine Midbrain dopamine neurons release GABA too They stimulate the reception of dopamine by neurons within crucial motor areas and cause neurons to react as they would to dopamine. GABA can also inhibit or reduce neuronal activity – so medications just targeting dopamine are not effective.

MICHAEL J FOX https://www.youtube.com/watch?v=ECkPVTZlfP8 https://www.youtube.com/watch?v=v8JCzz0tCds