# Motivation and emotion/Book/2024/Vasopressin and motivation

* Multimedia presentation (3 min)

## Overview

* Scenario
* You no longer feel yourself. There is very little motivation for you to do anything, and you really do not feel like socialising at all. Your mood is also very negative lately and you are very irritable with others. You wonder if you have depression and also realise that since your dentist told you to give up carbonated drinks, that you don't really drink very much at all. What is going on?
This book chapter explains the role of Vasopressin, also known as antidiuretic hormone (ADH), and the effect it has on motivation. From its role as a hormone regulating the urinary pathway, the physiological role (see Figure 1) is then further explored on the affect vasopressin has on motivation and emotion. Recent research has investigated the role of vasopressin in social behaviour, and key research and theories include:
* The role vasopressin plays in pair bonding between partners during sexual activity (DiBenedictos et al., 2020).
* How vasopressin affects motivation differently depending on the sex of the person (Feng et al., 2015).
* How vasopressin and oxytocin work together to affect mood and motivation (Febo & Ferris, 2014).
* Case study: David
* David has been feeling sluggish lately, with no motivation and very irritable. He works shift work as a barista and although he is always serving other people drinks, he has not been drinking enough himself. He was told recently by his doctor that he had signs of mild dehydration with concentrated urine and red eyes even after a full night's sleep.
* David wonders how much the lack of fluids have impacted his mood as he has been thinking about a recent article he read about vasopressin, with studies showing how it affects people socially. David also knows from his studies that the secretion of vasopressin is affected by the amount of body fluid a person has. David is now wondering if he increased the amount he drank, if it would improve his mood and motivation...?
* Focus questions:
* What is vasopressin ?
* What is the physiological pathway of vasopressin ?
* How does vasopressin affect motivation ?

## What is vasopressin?

* Arginine vasopressin is a hormone that regulates the urinary pathway with the primary function to maintain body fluid balance by keeping plasma osmolality within limits[factual?]. This is done through regulating kidney function to excrete water together with the body's thirst mechanism and the specific role of vasopressin cannot be replaced (Bankir et al., 2017).
* Vasopressin is a cyclic nonapeptide containing nine amino acids and derived from the preprohormone called prepropressophysin, which contains a signal peptide, neurophysin II, and a glycoprotein (Cuzzo et al., 2023)[explain?].
* How we know the role of vasopressin has changed over time, to extend from managing body fluid to now understanding how it can modulate motivation and emotion[improve clarity]. Research studies show that both the vasopressin receptors AVPr 1a and AVPr 1b are significant in explaining how vasopressin modulates social behaviour, with AVPr 1b being identified as playing a role in regulating the endocrine stress response (Stevenson & Caldwell, 2015)[explain?].

## What is the physiological pathway of vasopressin?

Vasopressin[grammar?] physiological pathway starts with the hypothalamus (Stevenson & Caldwell, 2015) and is released into the bloodstream with a relatively short life span before being filtered through the kidneys.This results in vasopressin acting relatively quickly with regulation of body fluid volume (Bankir et al., 2017).

### Where is vasopressin made?

The vasopressin hormone originates from the hypothalamus and is stored in the neurohypophysis[factual?]. Prepropressophysin which includes vasopressin as well as copeptin and neurophysin II are separated in the pituitary and released into the bloodstream in equimolar amounts[factual?]. The half-life of vasopressin is approximately 3 minutes and is cleared from the blood stream through filtration of the kidneys[factual?]. As a result, the effects of vasopressin are relatively quick in how it modulates body fluid balance (Bankir et al., 2017).

## How do the vasopressin receptors work?

The three receptors for vasopressin (AVPr 1a, AVPr 1b and AVPr 2) are located throughout the body (see Table 1.), however only AVPr 1a and AVPr 1b are located centrally. AVPr 1b is found in the pancreas where it is linked to insulin release and in the adrenal gland where it facilitates catecholamine release in response to stress. AVPr 1b is also located in the anterior pituitary gland and the brain (Stevenson & Caldwell, 2015).
Table 1.
Vasopressin receptors with locations and actions within the body
| | Loacations[spelling?] | Actions |
| AVPr 1a | Brain, periphery blood vessels, kidneys, liver | Blood sugar regulation, vasoconstriction, social recognition |
| AVPr 1b | Brain, pituitary gland, adrenal gland, pancreas | Catecholamine release in response to stress, social interpretation |
| AVPr 2 | Kidneys | Water reabsorption along osmotic gradient to regulate blood volume |

### How is vasopressin related to blood pressure?

Vasopressin has been shown[factual?] to play a secondary role in managing blood pressure, in people with impaired autonomic nervous system function. With decreased blood volume as a result of heart failure or other impairments, vasopressin secretion increases (Jordan et al., 2000). The primary role for regulation of blood pressure however is through the hormone copeptin (Bankir et al., 2017).

## How does Vasopressin influence motivation?

* How vasopressin affects the mood, and motivation has been shown to be different depending on sex[factual?]. Research has shown that vasopressin activation in males when compared to a placebo group, increases the salience of positive social interaction, while decreasing positive social interaction amongst women[factual?]. In addition, research has shown that only for women, positive cooperation decreased with vasopressin activation compared with men (Feng et al., 2015).
* Vasopressin has an important role in sexual partnership. Through research on sex motivation of rat populations, it has been shown that there was an increased amount of AVPr 1a receptors in the male rat population compared to the female rat population[factual?]. It has also been shown that by blocking the signaling of the AVPr 1a receptor, it reduced the sociosexual motivation of the male rats, while increasing the sociosexual motivation of the female rats (DiBenedictos et al., 2020).
* Vasopressin and oxytocin have been shown to work together to modulate emotional states through research involving magnetic imaging of both vasporessin and oxytocin activation in the brains of rats[factual?]. This research showed that oxytocin was released with the lactating female rat brain[factual?]. Vasopressin and oxytocin were shown to be active in their role in motivational and emotional states of aggression, maternal care and unconditioned fear, through modulation of the hormones themselves and their receptors[factual?]. The brain regions shown to be affected are the basal forebrain, amygdalar nuclei, midbrain regions and the subregions of the cortex (Febo & Ferris, 2014).
* How the amount of fluid someone drinks can affect vasopressin levels and motivation was studied, with research showing that increasing drinking behaviour results in a mild increase in oxytocin and vasopressin[factual?]. This decreases stress axis activity, increases relaxation and social bonding and inhibitds[spelling?] fear (Pruimboom & Reheis, 2016).

## Conclusion

Vasopressin is a cyclic nonapeptide hormone (Stevenson & Caldwell, 2015), that is produced by the hypothalamus with it's[grammar?] primary function to maintain body fluid balance by keeping plasma osmolality within limits (Bankir et al., 2017). Three receptors (AVPr 1a, AVPr 1b and AVPr 2), located throughout the body play a role in regulating and modulation of the physiological effects of vasopressin. Primarily AVPr 1a and AVPr 1b, are significant in modulation of the social effects of vasopressin with AVPr 2 being significant in regulation of body fluid balance (Stevenson & Caldwell, 2015). Vasopressin also has a secondary role to copeptin in regulating blood volume (Jordan et al., 2000).
How vasopressin affects mood and motivation is dependent on sex, with vasopressin activation increasing positive cooperation amongst men and decreasing cooperation amongst women (Feng et al., 2015)[why?]. Research also shows that vasopressin blockage decreases socio-sexual motivation for male rats and increases this for female rats (DiBenedictos et al., 2020). Further research shows how oxytocin and vasopressin work together with magnetic imaging showing the activation of AVPr 1a and AVPr 1b receptors in brain regions including the forebrain, midbrain and cortex, when modulating motivational and emotional states such as aggression, maternal care and fear response (Febo & Ferris, 2014). This highlights the importance of vasopressin and fluid intake being not just a physical need but also the significant role vasopressin has in regulating positive social interaction and motivation (Pruimboom & Reheis, 2016).