Cajal famously described the fly visual system as “stupendous, indeed disconcerting, and with no precedent in other animals”. By comparison, the vertebrate retina seemed “gross and deplorably simple”. Now we know that this simplicity is only apparent, but we can use the more clearly structured fly retina to help us study basic problems in visual […]
It was commonly assumed that no new neurons are formed in the adult mammalian brain, even after the first results showing neurogenesis in rodents were published in the 1960s. Further work in mammals and birds during the 80s contributed to change the scientific consensus, but it was the discovery of adult neurogenesis in humans in […]
Our brain constitutes one of the finest pieces of natural machinery known, and it allows us to efficiently interact with our environment: searching for food, avoiding predators, communicating with other individuals, and even some more sophisticated stuff — like enjoying a well composed piece of classical (or rock) music. However, all this comes at a […]
Biomedicine • Materials • Neurobiology • Physics • Physiology
Human brain has about 85 billion neurons. Each neuron forms thousands of chemical and electrical synapses with other neurons. To record the synaptic activity of each neuron in the brain an intracellular probe with a millivolt scale is required. Glass electrodes are widely used, but they are fragile and they have high impedance. An intracellular […]
In our eyes, the cornea and crystalline lens project an image of the world onto the retina. There, this image is sampled by the rods and the cones —the light-sensitive cells of the vertebrate eye—, coded as a sequence of electrical signals and preprocessed by other neurons before being sent to the brain via the […]
Bees visit flowers to obtain nectar (a sugary liquid) and pollen (their source of fat and protein). During foraging trips, bees do not choose flowers at random. For example, as first pointed out by Aristotle, bees visit only one type of flower in each of their foraging trips. How do bees recognise flowers? Colour textures […]
From a certain point of view, eukaryotic cells could be described as microscopic power plants equipped with factories and energy-generating platforms, inside of which highways and compartments are constantly built and rebuilt, and a fluent traffic provides a constant recycling of structures while getting rid of garbage. The trafficking also involves material coming in and […]
About 95% of the photoreceptors in our retina are rods, which we use for nocturnal vision, since they can detect single photons. During the day, rods saturate, and we use the other 5% of photoreceptors, the cones, which mediate color vision and do not saturate even at the highest light levels. There is still a […]
Olfaction is one of the most important senses. It protects us from eating spoiled food, it helps animals to detect their relatives, it makes the perfume business quite successful and, in general, it connects us to the volatile chemicals surrounding us. These chemicals, usually called “odorants”, can be detected even if they are in a […]
Neurons in your brain are interconnected through synapses, thus constituting the so-called neural networks. Following a simplified but conceptually useful view, each synapse can be seen as a “link” between two given neurons, and it has a certain associated strength. Such a strength gives an idea of how reliable a given synapse is in order […]