The thyroid axis, also known as the hypothalamic-pituitary-thyroid (HPT) axis, is a crucial neuroendocrine system involved in regulating thyroid hormone production and maintaining overall metabolic homeostasis. This axis involves complex interactions between the hypothalamus, pituitary gland, and thyroid gland, and its functions have significant implications in neuroscience and brain function.The HPT axis functions through a feedback loop, starting with the hypothalamus secreting thyrotropin-releasing hormone (TRH). TRH then stimulates the anterior pituitary gland to release thyroid-stimulating hormone (TSH) into the bloodstream. TSH, in turn, targets the thyroid gland, stimulating the production and secretion of thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). The primary mode of action for thyroid hormones is through binding to nuclear receptors known as thyroid hormone receptors (THR), which act as ligand-activated transcription factors. In the absence of thyroid hormones, THR is usually bound to co-repressors, which inhibit gene transcription. However, when T3 binds to THR, it causes a conformational change that leads to the release of co-repressors and the recruitment of co-activators. This co-activator complex then promotes the transcription of target genes. The activated THR-co-activator complex binds to specific DNA sequences called thyroid hormone response elements (TREs) located in the promoter regions of target genes, leading to the initiation of gene transcription. Thyroid hormones can affect the expression of a wide range of genes involved in metabolism, growth, and development. The functions of the thyroid axis in neuroscience are diverse and critical for brain development, cognition, mood regulation, and overall neural function. For example, thyroid hormones play a key role in brain development, particularly during foetal development and early childhood. Adequate thyroid hormone levels are essential for neuronal migration, synaptogenesis, and myelination and deficiencies in thyroid hormone during critical periods of brain development can lead to irreversible cognitive impairments and intellectual disabilities, a condition known as congenital hypothyroidism. Thyroid hormones also influence cognitive function, memory, and learning. Optimal thyroid hormone levels are associated with improved cognitive performance, attention, and memory consolidation. Hypothyroidism, characterized by insufficient thyroid hormone production, can lead to cognitive impairments, memory deficits, and difficulty with concentration. Thyroid hormones also influence mood and emotional regulation. Hypothyroidism is often associated with symptoms of depression, whilst hyperthyroidism, characterized by excessive thyroid hormone production, can lead to anxiety, irritability, and restlessness. Thyroid hormones are also critical for regulating metabolism in various tissues, including the brain. They influence energy expenditure, thermogenesis, and nutrient metabolism. Hypothyroidism can therefore lead to a decrease in metabolic rate, weight gain, and alterations in lipid and carbohydrate metabolism. Thyroid hormones also have neuroprotective effects on the brain. They can help protect neurons from oxidative stress, inflammation, and apoptosis. As a result, adequate thyroid hormone levels are essential for maintaining brain health and preventing neurodegenerative disorders. Finally, thyroid hormones can influence sleep-wake cycles and circadian rhythms. Disruptions in thyroid function, such as in hyperthyroidism or hypothyroidism, can lead to sleep disturbances and insomnia. We provide a comprehensive product catalogue of research reagents for investigating the thyroid axis, including Thyroid Peroxidase antibodies, TSH Receptor antibodies, TSH beta antibodies, TSH alpha antibodies, and TSH alpha ELISA Kits. Explore our full thyroid axis product range below and discover more, for less.