What is the Difference Between Amygdala and Hypothalamus

The main difference between amygdala and hypothalamus is that amygdala is the emotion center of the brain whereas the hypothalamus has neuroendocrine functions.

In brief, the amygdala and hypothalamus are two structures of the limbic system of the brain and are involved in the generation of emotions.

Key Areas Covered

1. What is Amygdala
– Definition, Structure, Function
2. What is Hypothalamus
– Definition, Structure, Function
3. Similarities Between Amygdala and Hypothalamus
– Outline of Common Features
4. Difference Between Amygdala and Hypothalamus
– Comparison of Key Differences

Key Terms

Amygdala, Hypothalamus

What is Amygdala

Amygdala is one of the two clusters of nuclei that are almond-shaped. It is also responsible for various hormonal secretions, emotional responses, and memory functions. It is located in the deep and medially in the temporal lobes of the cerebrum of the brain. The primary role of the amygdala is the processing of memory, decision-making, and emotional responses. Moreover, reciprocal associations of the amygdala occur with the central nervous system, thalamus, hypothalamus, septal nuclei, orbital frontal cortex, cingulate gyrus, hippocampus, parahippocampal gyrus, and brain stem.

Figure 1: Amygdala

Furthermore, there are two major regions of the amygdala. They are centro-corticomedial nuclei that activate the body’s natural instinct of “fight or flight” and basolateral nuclei that activates the fear response. Apart from that, the amygdala plays a vital role in storing memories, generating strong affective reactions such as fear, anger, emotions associated with sexual behavior, hormonal secretions, arousal, fighting behavior, and mating and maternal care.

What is Hypothalamus

The hypothalamus is the region of the forebrain and is just below the thalamus, connecting to both lobes of the pituitary gland. Specifically, the hypothalamus connects the anterior pituitary gland by means of a portal blood system communicating through chemical signals, thus, stimulating and inhibiting hormones. Meanwhile, it directly connects to the posterior pituitary through neurons. Thereby, the hypothalamus regulates the functions of the pituitary gland.

Figure 2: Hypothalamus

Moreover, the posterior pituitary gland stores and releases hormones produced by the hypothalamus, including the antidiuretic hormone and oxytocin. However, dopamine, somatostatin, corticotrophin-releasing hormone (CRH), growth hormone-releasing hormone (GHRH), thyrotrophin-releasing hormone (TRH), and gonadotrophin-releasing hormone (GnRH) are the hormones produced by the hypothalamus. These are sent to the anterior pituitary gland for secretion. In the meanwhile, the hypothalamus is also responsible for regulating blood pressure, the levels of circulating hormones, body temperature, hunger, thirst, sleep, and emotional activity.

Similarities Between Amygdala and Hypothalamus

• The amygdala and hypothalamus are the structures of the brain.
• Both structures together are called the limbic system and it is important as the emotional center of the brain.

Difference Between Amygdala and Hypothalamus

Definition

Amygdala refers to a region of the brain primarily associated with emotional processes. In contrast, the hypothalamus refers to the area of the brain that produces hormones that control body temperature, heart rate, hunger, and mood.

Anatomy

Amygdala is an almond-shaped mass of nuclei while the hypothalamus contains three main regions anterior region, middle region, and posterior region.

Location

Amygdala is located in the medial temporal lobe, just anterior to (in front of) the hippocampus. Meanwhile, the hypothalamus is located below the thalamus and above your pituitary gland.

Function

The amygdala primarily involves in the processing of emotions and memories associated with fear while the hypothalamus is responsible for maintaining the body’s homeostasis.

Conclusion

In brief, Amygdala and hypothalamus are two structures of the brain that form the limbic center. The limbic center is responsible for motivation, emotion, learning, and memory. Amygdala is an almond-shaped mass of nuclei located in the medial temporal lobe anterior to the hippocampus. Moreover, the main function of the amygdala is to process emotions and memories. Hypothalamus, on the other hand, is located below the thalamus and above the pituitary gland. It contains three regions: the anterior region, the middle region, and the posterior region. In addition, the main function of the hypothalamus is to maintain the homeostasis of the body. Therefore, the main difference between amygdala and hypothalamus is their structure and function.       

References:

1. “Amygdala.” Wikipedia, Wikimedia Foundation, 21 Oct. 2022,
2. “Hypothalamus.” Wikipedia, Wikimedia Foundation, 2 Nov. 2022,

Image Courtesy:

1. “Constudoverbrain” By RobinH – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “1806 The Hypothalamus-Pituitary Complex” By OpenStax College – Own Work (CC BY 3.0) via Commons Wikimedia