Neurochimie | EPFL Graph Search

Neurochemistry is the study of chemicals, including neurotransmitters and other molecules such as psychopharmaceuticals and neuropeptides, that control and influence the physiology of the nervous system. This particular field within neuroscience examines how neurochemicals influence the operation of neurons, synapses, and neural networks. Neurochemists analyze the biochemistry and molecular biology of organic compounds in the nervous system, and their roles in such neural processes including cortical plasticity, neurogenesis, and neural differentiation. While neurochemistry as a recognized science is relatively new, the idea behind neurochemistry has been around since the 18th century. Originally, the brain had been thought to be a separate entity apart from the peripheral nervous system. Beginning in 1856, there was a string of research that refuted that idea. The chemical makeup of the brain was nearly identical to the makeup of the peripheral nervous system. The first large leap forward in the study of neurochemistry came from Johann Ludwig Wilhelm Thudichum, who is one of the pioneers in the field of "brain chemistry." He was one of the first to hypothesize that many neurological illnesses could be attributed to an imbalance of chemicals in the brain. He was also one of the first scientists to believe that through chemical means, the vast majority of neurological diseases could be treated, if not cured. Irvine Page (1901-1991) was an American psychologist that published the first major textbook focusing on neurochemistry in 1937. He had also established the first department that was solely devoted to the study of neurochemistry in 1928 at the Munich Kaiser Wilhelm Institute for Psychiatry. Back in the 1930s, neurochemistry was mostly referred to as "brain chemistry" and was mostly devoted to finding different chemical species without directly proposing their specific roles and functions in the nervous system. The first biochemical pathology test for any brain disease can be attributed to Maria Buscaino (1887-1978), a neuropsychiatrist who studied schizophrenia.

In vivo neurochemistry of the ventral striatum and social competition in Homo sapiens

Alina Veronika Irene Strasser

Ventral striatal function and trait anxiety have been shown to influence reward-seeking behaviour and social competition in humans. Moreover, social status perceptions have been shown to modulate ventral striatal function. The neurochemical underpinnings of these associations have not been investigated in humans so far. Studies in rodents have previously shown that ventral striatal neurochemistry is associated with these concepts. In humans, objective and perceived social hierarchy position show some links to physical and mental health. Trait anxiety is understood as a predisposing factor underlying neuropsychiatric disorders and is associated with social anxiety. Fear and avoidance of social interactions, both inherent to environmental contexts of direct social competition, are hallmarks of social anxiety. Lost economic productivity due to anxiety and social status associated decrements in physical and mental health renders this scientific topic of high relevance to public health policies. Moving towards a deeper understanding of these associations might constitute an important part in ensuring public health. We combine proton magnetic resonance spectroscopy with personality profiling and an incentivised handgrip motivation task in a socially competitive context to investigate the neurochemical underpinnings of these associations in young adult men. We chose the occipital lobe as a control region. In addition, we have measured the salivary biomarkers cortisol, testosterone and alpha-amylase. We found that trait anxiety is negatively linked to taurine and positively to the excitation-inhibition balance. State anxiety was positively linked to lactate. The salivary biomarker alpha-amylase was found to be associated with both state anxiety and lactate. Social anxiety was positively linked to the excitation-inhibition balance. We also show links between reward-seeking task performance and ventral striatal glutamine, phosphorylethanolamine, GABA, choline, glutathione, myo-inositol, the excitation-inhibition balance and the ratio of glutamine to glutamate. These associations were observed in the ventral striatum but not the occipital lobe. Our methodological approach allowed us to gain a deeper understanding of the neuroscience underlying the links between ventral striatal function, anxiety and motivated behaviour. Thereby, we have extended the literature on the links between personality traits, social status and motivated behaviour in socially competitive contexts and the underlying neurobiology. These new findings pave the way for future experimental investigations to further elucidate the links between neurochemistry, mental health and socially competitive behaviour. A deep understanding of the neuroscience underlying personality traits and performance allow for effective interventions with the goal to ensure public health.

EPFL2017

In vivo neurochemistry of the ventral striatum and social competition in Homo sapiens

Alina Veronika Irene Strasser

EPFL2017