OPTION E E4 NEUROTRANSMITTERS AND SYNAPSES

E.4.1 STATE THAT SOME PRESYNAPTIC NEURONS EXCITE POST SYNAPTIC TRANSMISSION WHILE OTHERS INHIBIT POST-SYNAPTIC TRANSMISSION. Pre-synaptic neurons can either excite or inhibit post-synaptic transmissions. (AP = “______________”) This depends on which __________________(NT) is used and which _______________ they bind to.

Excitatory: NT __________ an AP in the post-synaptic neuron E.4.1 STATE THAT SOME PRESYNAPTIC NEURONS EXCITE POST SYNAPTIC TRANSMISSION WHILE OTHERS INHIBIT POST-SYNAPTIC TRANSMISSION. Excitatory: NT __________ an AP in the post-synaptic neuron NT binding to the receptors opens _________ gates, causing sodium to flow in, ______________ the neuron. Na+ in, neuron _________________, depolarization occurs. NT: e.g. glutamate, acetylcholine (Ach), norepinephrine (NE), _____________

Inhibitory: NT __________ an AP in the post-synaptic neuron E.4.1 STATE THAT SOME PRESYNAPTIC NEURONS EXCITE POST SYNAPTIC TRANSMISSION WHILE OTHERS INHIBIT POST-SYNAPTIC TRANSMISSION. Inhibitory: NT __________ an AP in the post-synaptic neuron NT binding to the receptors opens __________ gates, causing chloride to flow in, _________________ the neuron. Cl- in, neuron _______________, more difficult to depolarize, impulse ____________. NT: e.g. _______, dopamine

____________ = -Aminobutyric acid E.4.1 STATE THAT SOME PRESYNAPTIC NEURONS EXCITE POST SYNAPTIC TRANSMISSION WHILE OTHERS INHIBIT POST-SYNAPTIC TRANSMISSION. ____________ = -Aminobutyric acid GABA is a NT that opens _______________________ on the post- synaptic membrane. Cl- rushes in, _____________________ the post-synaptic neuron and _____________ APs. GABA is important in regulating nervous processes – a “_____________” or depressive effect (reducing activity). It prevents neurons from __________, and can be used as a drug to help people with anxiety or stress-related disorders. ________ mimics the effect of GABA, further increasing hyperpolarization and therefore greatly reducing nerve activity.

Important points to remember: E.4.2 Explain how decision-making in the CNS can result from the interaction between the activities of excitatory and inhibitory presynaptic neurons at synapses. Important points to remember: - ________ of many neurons feed into the _________ of the post-synaptic neuron - each axon contributes to the _____________________ of the - effects of the each input can be either ___________ or ____________ - effect is ____________ and is added up at the _________________.

multiple _________ from one input E.4.2 Explain how decision-making in the CNS can result from the interaction between the activities of excitatory and inhibitory presynaptic neurons at synapses. If the summative effect of the inputs reaches _____________, an AP is propagated. Spatial Summation: multiple __________ Temporal Summation: multiple _________ from one input http://hsc.uwe.ac.uk/synapses_neuro/summation.htm

Excitatory drugs Inhibitory drugs E.4.3 Explain how psychoactive drugs affect the brain and personality by either increasing or decreasing postsynaptic transmission. Excitatory drugs Inhibitory drugs Block re-uptake pumps for NTs - NT __________________ e.g. cocaine’s effect on dopamine Mimic inhibitory NTs ________________ of post-synaptic neuron _______ APs e.g. alcohol mimics GABA effects, reducing APs Mimic excitatory NTs __________________, _______ APs e.g. nicotine Blocks excitatory NTs ___________ APs e.g. opiates (heroin) block pain pathway by competitive inhibition Block inhibitory NTs - prevent _______________ e.g. caffeine competitively inhibit adenosine http://outreach.mcb.harvard.edu/animations/synapse.swf

_______: stimulate alertness and memory, nausea and vomiting E.4.4 List three examples of excitatory and three examples of inhibitory psychoactive drugs. Excitatory _______: stimulate alertness and memory, nausea and vomiting _________________: increases heart rate, respiration, alertness _________________: causes anxiety and psychosis. http://www.jellinek.nl/brain/index.html

___________________: muscle relaxant, reduces anxiety. E.4.4 List three examples of excitatory and three examples of inhibitory psychoactive drugs. Inhibitory ___________________: muscle relaxant, reduces anxiety. ________: slows and prevents movement, impairs reasoning skills. ________: reduces heart rate, breathing rate, and blood pressure. http://www.jellinek.nl/brain/index.html

Excitatory drugs = Cocaine E.4.5 Explain the effects of THC and cocaine in terms of their action at synapses in the brain. Excitatory drugs = Cocaine Normal: Dopamine acts as an ___________________ Dopamine is ______________ at the pre-synaptic neuron pumps With Cocaine: ____________________ on reuptake pump Dopamine not re-uptaken; remains in __________________ _________ dopamine is released _____________ post-synaptic transmission Effect on mood/behavior Enhanced feelings of ___________(dopamine is a “pleasure” NT) ___________ energy and alertness Highly ___________ Associated with ____________ (body reduces its own dopamine) http://thebrain.mcgill.ca/flash/i/i_03/i_03_m/i_03_m_par/i_03_m_par_cocaine.html#drogues

Inhibitory drugs = THC (cannibis) E.4.5 Explain the effects of THC and cocaine in terms of their action at synapses in the brain. Inhibitory drugs = THC (cannibis) Normal: Two pathways to consider 1) pathway released _________, increasing feelings of ________ 2) _______ has an ___________ effect on release of dopamine With THC: Inhibits _________________ by binding to __________________ GABA cannot _______________ __________ dopamine is released ___________ post-synaptic transmission Effect on mood/behavior Enhanced feelings of __________ (dopamine is a “pleasure” NT) ______________ (drunk feeling), hunger, memory impairment http://thebrain.mcgill.ca/flash/i/i_03/i_03_m/i_03_m_par/i_03_m_par_cannabis.html#drogues

E4.6 Discuss the causes of addiction, including genetic predisposition, social factors, and dopamine secretion. Addiction - a __________________________disorder with genetic, psychosocial and environmental characteristics. - is characterized by changes in the brain resulting in a ______________________to use a drug. - “___________________” in the brain play a key role in reinforcing behavior that may lead to addiction.

E4.6 Discuss the causes of addiction, including genetic predisposition, social factors, and dopamine secretion. Reward Pathway - makes one feel good when he/she engages in behaviors that are ______________________(e.g. eating, drinking) ____________ is the NT most prevalent in the reward pathway. - generate a feeling of ___________ - high levels of dopamine cause a feeling of ___________ - user may seek to repeat by using the drug again (____________) - ____________ of the drug leads to anxiety, depression and craving

E4.6 Discuss the causes of addiction, including genetic predisposition, social factors, and dopamine secretion. Some people are ______________ more pre-disposed to becoming addicted than others. May be the result of genetically determined deficiency of __________________________ The children of addicts are ______________ to become addicts themselves.

E4.6 Discuss the causes of addiction, including genetic predisposition, social factors, and dopamine secretion. Psychosocial factors are a heavy influence in addiction: