oxytocin and Dementia

Oxytocin (OT) subserves various physiological, behavioral, and cognitive processes. This paired with the ability to administer OT with minimal and inconsistent side effects has spurred research to explore its therapeutic potential. Findings from single-dose studies indicate that OT administration may be beneficial, at least under certain circumstances. The state of the field, however, is less clear regarding effects from chronic OT administration, which more closely resembles long-term treatment. To address this gap, this review synthesizes existing findings on the use of chronic OT administration in animal and human work. In addition to detailing the effects of chronic OT administration across different functional domains, this review highlights factors that have contributed to mixed findings. Based on this review, a basic framework of interrelated regulatory functions sensitive to chronic OT administration is offered. The paper also identifies future research directions across different contexts, populations, and outcomes, specifically calling for more systematic and standardized research on chronic OT administration in humans to supplement and expand what is currently known from preclinical work.

Topics: Animals; Anxiety; Autism Spectrum Disorder; Dementia; Humans; Inflammation; Oxytocin; Pain; Schizophrenia; Sexual Dysfunction, Physiological; Stress Disorders, Post-Traumatic; Stress, Psychological; Substance-Related Disorders

This review focuses on the anti-dementia and antidepressant-like effects of peptides including glucagon-like peptide (GLP)-1, GLP-2, neuromedin U (NmU), and oxytocin, and the intranasal delivery of these peptides to the brain. Intracerebroventricularly administered GLP-1, NmU, and oxytocin improved impairment of learning and memory in mice treated with lipopolysaccharide or β-amyloid protein. GLP-1 also improved impairment of learning and memory in juvenile diabetes model rats. On the other hand, GLP-2 exhibited antidepressant-like effects in mice during the forced-swim test, which were associated with 5-HT

Topics: Administration, Intranasal; Animals; Brain; Dementia; Depression; Drug Delivery Systems; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Mice; Neuropeptides; Oxytocin; Peptides; Rats

The amygdala is a complex structure playing primary role in the processing and memorizing of emotional reactions. The amygdalae send impulses to the hypothalamus for activation of the sympathetic nervous system, to the reticular nucleus for increasing reflexes, to the nuclei of the trigeminal nerve and facial nerve for facial expressions of fear, and to the ventral tegmental area, locus coeruleus, and laterodorsal tegmental nucleus for activation of dopamine, norepinephrine and epinephrine release. The amygdala plays a key role in what has been called the "general-purpose defense response control network" and reacts in response to unpleasant sights, sensations, or smells. Anger, avoidance, and defensiveness are emotions activated largely by the amygdale. The amygdala is responsible for activating ancestral signs of distress such as "tense-mouth" and defensive postures such as crouching. Poor functioning of amygdala has also been associated with anxiety, autism, depression, narcolepsy, post-traumatic stress disorder, phobias, frontotemporal dementia, and schizophrenia. Impairment of emotional event memory in patients with Alzheimer's disease also correlates with the intensity of amygdalar damage. All these events speak out for the importance to preserve the normal function of the amygdala which can only be achieved by constant deepening of our knowledge about this unique structure.

Topics: Alzheimer Disease; Amygdala; Anxiety Disorders; Autistic Disorder; Corticotropin-Releasing Hormone; Dementia; Emotions; gamma-Aminobutyric Acid; Humans; Neurotransmitter Agents; Oxytocin; Schizophrenia; Vasopressins

A recent study has shown that vasopressin (AVP) cells in the human supraoptic (SON) and paraventricular (PVN) nuclei increase in size after 60 years of age, suggesting that AVP production is increased in senescence. In the present study, the same brain material was used for the determination of nucleolar size in immunocytochemically identified AVP and oxytocin (OXT) neurons as an additional parameter for peptide production. A strong correlation was found between nucleolar size and cell size, both in AVP and OXT neurons. Nucleolar size of AVP but not of OXT neurons increased significantly in senescence. Observations in brains from patients with senile dementia of the Alzheimer type (SDAT) were commensurate with their ages. These results strongly support the hypothesis that AVP neurons in the SON and PVN are activated in old age.

Topics: Adolescent; Adult; Aged; Aging; Arginine Vasopressin; Cell Nucleolus; Child; Dementia; Humans; Immunoenzyme Techniques; Middle Aged; Oxytocin; Paraventricular Hypothalamic Nucleus; Supraoptic Nucleus