QUIZ 4 Flashcards
DOPAMINE
role in reward system and system in the forebrain regulates movement
dysfunction in the nigrostraital system - Parkinson’s disease symptoms
SEROTONIN
regulates appetite, sleep, memory, learning and mood
low levels in CSF - associated with depressive symptoms
nerve pathway to the brain called ‘raphe nuclei’
SSRI - prevent reuptake
NOREPINEPHRINE
fight or flight response
antagonist drugs - treat depression, anxiety and mania
elevated levels found in mania patients
GLUTAMATE
excitatory synpases in brain and spinal cord
used at modifiable synapes (alter in strength) which are key for memory storage elements
GABA
inhibitory synapses in the brain
glycine - inhibitory synapes in the spinal cord - together act as major inhibitors of the CNS
acts like a ‘break system’ - block excessive activity and maintain stability
tranquilisers are GABA agonists
ACETYLOCHINE
transmitter at junction connecting motor nerves and muscles - all motor movement achieved by ACh release
synapses with ACh receptors - nicotinic and muscarinic synapses (called cholinergic synapses)
ACETYLOCHINE
transmitter at junction connecting motor nerves and muscles - all motor movement achieved by ACh release
synapses with ACh receptors - nicotinic and muscarinic synapses (called cholinergic synapses)
Describe the role of autoreceptors and anoaxoic synapses in synaptic communication
Autoreceptors are preysnaptic receptors which monitor the quantity of neurotransmitter that the neuron releases and regulates the amount that it is synthesised and released. When activated, they can inhibit further release of the neurotransmitter (autoinhibition). By regulating neurotransmitter release, autoreceptors help regulate the overall activity of neuronal circuits.
Axoaxoic synapses are specialised synapses between the terminal of one neuron and the axon of another neuron. They also regulate neurotransmitter release through a process of presynaptic modulation. This involved presynaptic inhibition (decreasing the release) or presynaptic facilitation (increasing the release). This modulation effecrs synaptic trasmission and the overall function of neuronal circuits.
Describe the role of hormones in non-synaptic communication
Hormones are chemical messengers secreted by endocrine glands. Cells that contain receptors for that particular hormone are referred to as target cells.
Describe the ventricular system, the production of CSF, and its flow through the brain
CSF protects and provides the brain with nutrients. It is produced by the choroid plexus of the lateral ventricles and flows through the third ventricle, then through the cerebral aqueduct to the fourth ventricle. The CSF then leaves through small openings that connect with the subarachnoid space surrounding the brain. It then flows around the CNS where is is reabsorbed into the bloody supply.
Discuss the role of the ventromedial prefrontal cortex in anger, aggression and impulse control
the ventromedial prefrontal cortex is located in the frontal lobe. It is connected to multiple sections of the frontal lobes, including the hippocampus and the amygdala, meaning its outputs regulate a variety of emotional responses. It integrated information about the environment and is able to inhibit emotional responses. Anderson et al found that people with damage here were more irritable. Similar findings were found with the Phineas Gage case.
It also has a role in judgement and decision making. Damage to this region is associated with more utilitarian style decision making.
The prefrontal cortex also plays an important role in supressing impulsive behaviours in order to evade negative consequences. Impulsive behaviours have been associated with higher amygdala activity, an increased tendency for negative emotions and decreased activation of this area, and therefore a decreased ability to control the activity of the amygdala and people’s emotions.
Discuss research on the effects of REM sleep and slow-wave on learning
Slow-wave sleep and REM sleep play different roles in memory consolidation. Research suggests that REM sleep facilitates the consolidation of nondeclarative memories, whilst slow wave sleep facilitates the consolidation of declarative memories. Slow wave sleep has also been associated with navigation learning. There is still debate whether both forms of sleep are needed for memory and learning, for example there have been cases of people with REM disorder who can still successfully learn.
Describe the neural basis of arousal.
Acetycholine - high levels in the hippocampus and activating ACH neurons in the forebrain causes wakefulness
Norepinephrine - activity of noradrengenic neurons increases vigiliance. Activity of these neurons increase during periods of wakefulness
Serotonin - involved in numerous processes. Stimulation of the raphe nulcei causes movement and cortical arousal. Serotonin neurons are most active during waking, decline during sleep and then temporarily become very active after REM.
Histamine - receptors are located in the hippocampus. Activity of these receptors are high during wakefulness.
Orexin - activating orexin neurons in the hippocampus awakens animals from REM and non-REM sleep. They fire fastest when awake, and less frequently during quiet waking and sleep.
Discuss the interactions between stress, the immune system, and infectious diseases.
Chronic stress can have very negative impacts on the body. It can stunt growth, or even alter grey matter volume of the hippocampus. It can also suppress activity of the immune system through extended secretion of cortisol. Research has associated chronic stress with lower levels of B lymphocytes and T lymphocytes, and wounds taking longer to heal. Chronic stress has also been associated with weaker immune system responses, leading to a heightened risk of contracting acute infections such as the Epstein Barr virus.
Describe the neural basis of slow-wave sleep
Controlled by three factors - homestatic control (presence of adenosine), allostatic control (mediated by hormonal and neuronal responses to stress) and circadian rhythms.
It is also controlled by the sleep-wake flip flop. Inhibition of the arousal system is necessary for sleep Group of GABAnergicneurons in the ventro lateral preoptic area (vlPOA) become active and suppress activity of arousal neurons. Orexinergic neurons help to stabilise the sleep/waking flip/flop Motivation to remain awake, events that disturb sleep (hunger, biological clock etc) activate the orexinergic neurons. Orexinergicneurons receiving inhibitory input from the vlPOA.
