Molecular Biology

Neurophilosophy

Category archives for Molecular Biology

TRICHOTILLOMANIA (or hair pulling) is a condition characterised by excessive grooming and strong, repeated urges pull out one’s own hair. It is classified as an obsessive-compulsive disorder (OCD), and is relatively common, affecting about 2 in 100 people. Sufferers normally feel an increasing sense of tension before pulling out their scalp hair, facial hair, and…

SNAKES have a unique sensory system for detecting infrared radiation, with which they can visualize temperature changes within their immediate environment. Using this special sense, they can image the body heat radiating from warm-blooded animals nearby. This enables them to track their prey quickly and with great accuracy, even in the dark, and to target…

MicroRNAs regulate adult neurogenesis

It is now well established that the adult mammalian brain contains stem cells which continue to generate new neurons throughout life. This discovery, and subsequent research, has transformed the way we think about the brain. It is, for example, known that physical and mental exercise can stimulate the growth of new nerve cells in a…

Zebrafish brainbow bioscape

This beautiful image of the brain of a 5-day-old zebrafish larva, which was created by Albert Pan of Harvard University, has just won 4th place in the 2008 Olympus BioScapes Digital Imaging competition. (See a larger version here.) It was created using the Brainbow technique, a genetic method for labelling neurons, with which individual cells…

Memories are made of molecular motors

Learning and memory are widely thought to involve long-term potentiation (LTP), a form of synaptic plasticity in which a neuron’s response to the chemical signals it receives is enhanced. This leads to a strengthening of the neuronal circuit, so that the memory encoded in the circuit can persist for long periods of time. One of…

In his 1941 book Man on His Nature, the Nobel Prize-winning physiologist Sir Charles Sherrington described the brain as “an enchanted loom where millions of flashing shuttles weave a dissolving pattern.” Little could he have known that within 50 years neuroscientists would have at their disposal techniques for visualizing this pattern. These techniques are collectively…

Prion protein infection mechanism identified

The transmissible spongiform encephalopathies (TSEs), which include variant Creutzfeldt-Jakob Disease in humans, “Mad Cow” Disease in cattle and scrapie in sheep, are progressive and fatal neurodegenerative disorders characterized by the accumulation within nerve cells of an abnormally folded and insoluble form of the prion protein. The infectious agent which causes these diseases is generally believed…

Neuronal light switches

The September issue of Scientific American contains an excellent and lengthy article about a state-of-the-art technique called optogenetics, by molecular physiologist Gero Miesenböck, who has been instrumental in its development. As its name suggests, optogenetics is a combination of optics and genetic engineering. It is a powerful new method for investigating the function of neuronal…

National Library of Medicine / Hot Medical News This silent film clip shows several victims of a disease called kuru. They are – or rather were – members of the South Fore, a tribe of approximately 8,000 people who inhabit the Okapa subdistrict of the Eastern Highlands Province of Papua New Guinea. In the 1950s…

The eye tells the brain when to plasticize

The classic Nobel Prize-winning studies of David Hubel and Torsten Weisel showed how the proper maturation of the developing visual cortex is critically dependent upon visual information received from the eyes. In what would today be considered highly unethical experiments, Hubel and Weisel sewed shut one eye of newborn kittens. They found that this monocular…