Neurobiologists have long known that the euphoria induced by drugs of abuse aris
ID: 166813 • Letter: N
Question
Neurobiologists have long known that the euphoria induced by drugs of abuse arises because these chemicals stimulate the activity of the brain's reward system. Dopamine is a neurotransmitter involved in the stimulation of this reward system, e.g. - the Addicted Brain' by Eric J Nastier and Robert C Malenka Using you knowledge of how neurotransmitters and receptors interact to propagate a nerve signal across synapses, describe the process by which dopamine acts as such a neurotransmitter. Describe two mechanisms discussed in class that can control the amount of dopamine present in the synapse. Heroin and cocaine disrupt the normal dopamine signaling of the brain's reward system (but in different ways). Describe these disruption mechanisms.Explanation / Answer
1.Heroin and cocaine disrupt the normal dopamine signaling of the brain’s reward system (but in different ways). Describe this disruption mechanism.
Drugs interact with neurotransmission. These drugs produce the feeling of pleasure by changing the neurotransmission of neurons because dopamine released from neurotransmitter. Drugs alter the way of interaction in between neurons and dopamine.
Drugs alter that site of action synaptic transmission by increasing the amount of neurotransmitter released in between synaptic gap. Heroin and Cocaine increase the rate dopamine release from ventral tegmental area. The release of dopamine increases the action potential also. .
3.How neurotransmitters and receptors interact to propagate a nerve signal across synapses, describe the process by which dopamine acts as a neurotransmitter.
Neurons have ability to sending the electrical signals. The mechanism of signal sending is known as conduction. This signal transduction carries in between synapses which generate the action potential. Action potential is an electrical signal. The electrical signal in neuron release because ions moves in between the neuronal membrane.
The protein membrane of neuron acts as barrier to ions. These Ions move across the membrane through ion channels that open and close due in the presence of neurotransmitter. The inflow and outflow of ions will make the inside of the target neuron more positive. When this depolarization achive a point of no return a large electrical signal is generated. This is the action potential.
This signal then moves along the axon until it reaches its axon end terminals. Conduction ends at the axon terminals. Axon terminals are where neurotransmission begins. At chemical synapses, the output will be neurotransmitter. In chemical neurotransmission, the pre synaptic neuron and the postsynaptic neuron are separated by a small gap called synaptic cleft. The synaptic cleft is filled with extracellular fluid.