Tell a ‘story’ by describing how a neuronal impulse creates a cascade of events to occur within the neuron and between neurons. Imagine that you are explaining how neuronal activation occurs, and what the step-by-step processes are, as you would, to a fellow nurse practitioner that has not specialized in psychiatric nursing but is familiar with medical/biology terminology. Concepts/words that must be incorporated and explained throughout your ‘story’ includes: 300 -500 words and include at least four scholarly references in your work.
Title: A Journey into Neuronal Activation: Unveiling the Intricacies of the Nervous System
Introduction:
Within the intricate network of the human brain, a remarkable process known as neuronal activation takes place with stunning complexity and precision. Neuronal activation serves as the foundation for all brain functions and is responsible for carrying information, thoughts, and emotions throughout our bodies. In this narrative, we will embark on a journey to explore the step-by-step processes of neuronal activation, unraveling the cascade of events that occur both within individual neurons and between interconnected neurons.
Chapter 1: The Starting Point
Our journey begins at the synapse, a tiny gap that separates one neuron from another. At rest, a neuron maintains a polarized state, with a negative charge inside its cell membrane. This membrane possesses numerous ion channels, including voltage-gated sodium and potassium channels, which play a vital role in neuronal activation.
Chapter 2: The Stimulus
Now, imagine a summer breeze gently brushing across your skin. This external stimulus serves as the trigger for our neuronal activation story. Sensory neurons, located in the peripheral nervous system, can detect this stimulus through specialized receptors. These receptors convert the physical energy of the breeze into electrical signals, called action potentials, which are then transmitted towards the central nervous system.
Chapter 3: The Action Potential
As the sensory information arrives at the synapse, it encounters the first neuron in our story, the presynaptic neuron. The electrical signals, in the form of action potentials, are transported along the presynaptic neuron’s axon until they reach the terminal buttons, specialized structures located at the end of each axon.
Chapter 4: The Neurotransmitter Release
Upon reaching the terminal buttons, the action potentials stimulate the release of neurotransmitters, chemicals that act as messengers between neurons. These neurotransmitters are stored within synaptic vesicles, small structures within the terminal buttons. In response to the action potentials, these vesicles fuse with the presynaptic membrane, releasing the neurotransmitters into the synapse.
Chapter 5: The Synaptic Cleft
As the neurotransmitters are released from the presynaptic neuron, they venture across the synapse and enter the synaptic cleft, the gap between the presynaptic neuron and the postsynaptic neuron. Here, they float freely, awaiting the next phase of our story.
Chapter 6: The Postsynaptic Neuron
As our neurotransmitters wander through the synaptic cleft, they seek out their specific receptors on the postsynaptic neuron’s membrane. Each neurotransmitter has its own specific receptor, like a key fitting into a lock. When the receptor and neurotransmitter successfully bind, it initiates a change in the postsynaptic neuron’s membrane potential.
Chapter 7: The Membrane Potential Change
The binding of neurotransmitters to their receptors opens ion channels on the postsynaptic neuron’s membrane. Ion channels, such as ligand-gated sodium channels, allow positively charged ions, such as sodium, to enter the cell. This influx of positive ions generates a depolarizing effect, changing the membrane potential of the postsynaptic neuron from negative to positive.
Chapter 8: Excitatory or Inhibitory Response
The change in the membrane potential determines whether the postsynaptic neuron will be stimulated or inhibited. If the membrane potential reaches a certain threshold, excitatory neurotransmitters will trigger an action potential to be generated in the axon hillock, a specialized region of the neuron. This action potential will then travel along the axon, continuing the relay of information.
Alternatively, some neurotransmitters have inhibitory effects, preventing the generation of an action potential. These inhibitory neurotransmitters hyperpolarize the postsynaptic neuron’s membrane potential, making it less likely for an action potential to occur.
Chapter 9: The Journey Continues
As the action potential travels through the axon, it reaches the terminal buttons of the postsynaptic neuron, marking the end of our story. Here, the process of neurotransmitter release and transmission repeats, initiating the activation of the next set of neurons in the neural network.
Conclusion:
Neuronal activation is a fascinating journey that encompasses a series of intricate events. From the initiation of sensory stimuli to the release and binding of neurotransmitters, this captivating narrative sheds light on the beauty and complexity of the human nervous system. Understanding these processes underpins our understanding of psychiatric nursing and provides a solid foundation for future research and clinical practice.
References:
1. Kandel ER, Schwartz JH, Jessell TM, et al. Principles of Neural Science. 5th edition. New York: McGraw-Hill; 2013.
2. Purves D, Augustine GJ, Fitzpatrick D, et al. Neuroscience. 3rd edition. Sunderland, MA: Sinauer Associates; 2004.
3. Bear MF, Connors BW, Paradiso MA. Neuroscience: Exploring the Brain. 4th edition. Philadelphia, PA: Lippincott Williams & Wilkins; 2015.
4. Squire LR, Berg D, Bloom FE, et al. Fundamental Neuroscience. 4th edition. New York: Academic Press; 2012.