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The human brain contains 86 billion neurons, with 16 billion neurons in the cerebral cortex. [ 2 ] [ 1 ] Neuron counts constitute an important source of insight on the topic of neuroscience and intelligence : the question of how the evolution of a set of components and parameters (~10 11 neurons, ~10 14 synapses) of a complex system leads to ...
Frogs have a highly developed nervous system that consists of a brain, spinal cord and nerves. Many parts of frog brains correspond with those of humans. It consists of two olfactory lobes, two cerebral hemispheres, a pineal body, two optic lobes, a cerebellum and a medulla oblongata.
In their paper "What the Frog's Eye Tells the Frog's Brain", Lettvin et al. (1959) looked beyond the mechanisms for signal-noise discrimination in the frog's retina and were able to identify four classes of ganglion cells in the frog retina: sustained contrast detectors, net convexity detectors (or bug detectors), moving edge detectors, and net ...
In frogs and toads, the tympanum is a large external oval shape membrane made up of nonglandular skin. [2] It is located just behind the eye. It does not process sound waves; it simply transmits them to the inner parts of the amphibian's ear, which is protected from the entry of water and other foreign objects.
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord.The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts.
The relationship between brain size, body size and other variables has been studied across a wide range of vertebrate species. As a rule of thumb, brain size increases with body size, but not in a simple linear proportion. In general, smaller animals tend to have proportionally larger brains, measured as a fraction of body size.
An adult and two young under normal light (left) and UV light (right), showing that fluorescence varies with age Fluorescent patterns on the back of a pumpkin toadlet. B. ephippium is a very small frog with a snout–to–vent length of 12.5–19.7 mm (0.49–0.78 in) in adults, [5] but it is among the largest in its genus together with species like B. darkside, B. garbeanus and B. margaritatus.
In 1953, Horace Barlow described cells in a frog retina as "bug detectors", but the term did not gain wide usage. [4] [1] Several years later, Jerome (Jerry) Lettvin and others also studied these and other cells, eventually resulting in their widely known 1959 paper "What the frog’s eye tells the frog’s brain."