detection of temperature stimulus involved in thermoception

Definition

Target type: biologicalprocess

The series of events in which a temperature stimulus is received and converted into a molecular signal as part of thermoception. [GOC:ai, GOC:dos]

Thermoception, the sensation of temperature, is a complex biological process involving specialized sensory neurons called thermoreceptors. These receptors are distributed throughout the body, particularly in the skin and internal organs, and are responsible for detecting changes in temperature.

There are two main types of thermoreceptors: **warm receptors** and **cold receptors**. Warm receptors are activated by increases in temperature, while cold receptors are activated by decreases in temperature.

**Detection of Temperature Stimulus:**

1. **Stimulus:** When a temperature change occurs, it alters the physical properties of the thermoreceptors, such as the fluidity of cell membranes or the activity of ion channels.

2. **Transduction:** This alteration triggers a change in the electrical potential across the receptor membrane, known as a **receptor potential**. The receptor potential is proportional to the intensity of the temperature change.

3. **Signal Transduction:** The receptor potential initiates a cascade of events within the thermoreceptor, ultimately leading to the generation of an **action potential**. This electrical signal travels along the sensory neuron to the spinal cord and brain.

4. **Signal Transmission:** The action potential is transmitted via sensory neurons to the **thalamus**, a relay center in the brain. From the thalamus, the signal is projected to the **somatosensory cortex**, where the sensation of temperature is perceived.

**Mechanism of Thermoreceptor Activation:**

* **Warm Receptors:** These receptors contain ion channels that are sensitive to temperature changes. As temperature increases, these channels open, allowing positively charged ions to flow into the cell, depolarizing the membrane and generating a receptor potential.

* **Cold Receptors:** The activation of cold receptors is less well understood but is thought to involve the activation of **TRPM8 channels**, which are sensitive to both cold temperatures and menthol.

**Adaptation:**

Thermoreceptors can adapt to prolonged temperature exposure. After initial activation, the firing rate of thermoreceptors decreases, allowing for the perception of relative changes in temperature rather than absolute values.

**Clinical Relevance:**

Thermoception plays a crucial role in maintaining body temperature homeostasis, protecting against environmental extremes, and detecting potential threats, such as burns or frostbite. Dysfunction of thermoreceptors can lead to sensory disturbances, such as hypersensitivity to cold or heat.
'"

Proteins (2)

Compounds (70)