The role of orgasm in the development and shaping of partner preferences

Abstract

Background: The effect of orgasm on the development and shaping of partner preferences may involve a catalysis of the neurochemical mechanisms of bonding. Therefore, understanding such process is relevant for neuroscience and psychology.

Methods: A systematic review was carried out using the terms Orgasm, Sexual Reward, Partner Preference, Pair Bonding, Brain, Learning, Sex, Copulation.

Results: In humans, concentrations of arousing neurotransmitters and potential bonding neurotransmitters increase during orgasm in the cerebrospinal fluid and the bloodstream. Similarly, studies in animals indicate that those neurotransmitters (noradrenaline, oxytocin, prolactin) and others (e.g. dopamine, opioids, serotonin) modulate the appetitive and consummatory phases of sexual behavior and reward. This suggests a link between the experience of orgasm/sexual reward and the neurochemical mechanisms of pair bonding. Orgasm/reward functions as an unconditioned stimulus (UCS). Some areas in the nervous system function as UCS-detection centers, which become activated during orgasm. Partner-related cues function as conditioned stimuli (CS) and are processed in CS-detector centers.

Conclusions: Throughout the article, we discuss how UCS- and CS-detection centers must interact to facilitate memory consolidation and produce recognition and motivation during future social encounters.

Keywords: dopamine; ejaculation; opioids; orgasm; pair bonding; partner preference; sexual reward.

Fig. 1

Peripheral and central neurocircuitry involved in the development and shaping of orgasm-induced partner preferences. For full explanation, see Section ‘A model’. In RED, we depict the classic sensory input pathway: (1) peripheral nerves, (2) hindbrain, thalamus, and (3) sensory cortex (where orgasm is experienced). At the same time, (4) spino-cerebellar pathway projects information to (5) cerebellum, whose main output is via its deep nuclei, and also projects to (7) hypothalamus. (8) During orgasm, the hippocampus may process explicit and implicit memories. In BLACK, we depict a secondary ‘sensory’ pathway that involves (9) the vagus nerves and (10) hindbrain (nucleus of the tractus solitarious, periaqueductal gray matter), and from there to (7) hypothalamus.

Fig. 2

Central neurocircuitry involved in the development and shaping of orgasm-induced partner preferences. For full explanation, see Section ‘A model’. (1, 2) Sensory input projects to thalamus; (3) from thalamus to the sensory cortex where orgasm is experienced as pleasurable, and associative cortices where explicit memories of Who, When, and How the orgasm was experienced are processed. (4) Spino-cerebellar pathway projects information to the cerebellum where implicit memories may be processed in coordination with cortices. (5) Deep nuclei, the main cerebellar output to midbrain and hypothalamus. (6) The cerebellum-hypothalamic pathway. (7) Hypothalamus mediates sexual reward and motivation, and along with the medial amygdala may process social recognition and motivation. (8) Hippocampus may facilitate the crystallization between the experience of orgasm and cues on a partner. It can influence motivation via the mPOA to the midbrain ventral tegmental area (VTA), affecting the level of dopaminergic activity in ventral striatum (nucleus accumbens).