This article provides insufficient context for those unfamiliar with the subject.(March 2014) |
Dates in days
Day | Event | Reference |
---|---|---|
30 | retinal ganglion cell generation - start of neurogenesis | Robinson and Dreher (1990) |
30 | magnocellular basal forebrain - peak of neurogenesis | Finlay and Darlington (1995) |
30 | superficial superior collicus (SC) laminae - start of neurogenesis | Robinson and Dreher (1990) |
30 | raphe complex - peak of neurogenesis | Finlay and Darlington (1995) |
32 | locus coeruleus - peak of neurogenesis | Finlay and Darlington (1995) |
35 | posterior commissure appears | Ashwell et al. (1996) |
35.5 | medial forebrain bundle appears | Ashwell et al. (1996) |
36 | dorsal lateral geniculate nucleus (dLGN)- start of neurogenesis | Robinson and Dreher (1990) |
36 | optic axons at chiasm of optic tract | Dunlop et al. (1997) |
38 | deep cerebellar nuclei - peak of neurogenesis | Finlay and Darlington (1995) |
38 | amygdala - peak of neurogenesis | Finlay and Darlington (1995) |
39 | Purkinje cells - peak of neurogenesis | Finlay and Darlington (1995) |
39 | substantia nigra - peak of neurogenesis | Finlay and Darlington (1995) |
39.5 | subplate - start of neurogenesis | Robinson and Dreher (1990) |
39.5 | subplate -start of neurogenesis | Robinson and Dreher (1990) |
40 | internal capsule appears | Ashwell et al. (1996) |
40 | external capsule appears | Ashwell et al. (1996) |
40 | fasciculus retroflexus appears | Ashwell et al. (1996) |
40 | retinal horizontal cells - peak of neurogenesis | Finlay and Darlington (1995) |
41 | superior colliculus - peak of neurogenesis | Finlay and Darlington (1995) |
43 | subplate - peak of neurogenesis | Finlay and Darlington (1995) |
43 | dLGN -peak of neurogenesis | Finlay and Darlington (1995) |
43 | dLGN- end of neurogenesis | Robinson and Dreher (1990) |
43 | retinal ganglion cells - peak of neurogenesis | Finlay and Darlington (1995) |
43 | inferior colliculus - peak of neurogenesis | Finlay and Darlington (1995) |
45 | neurogenesis cortical layer VI - start (VC) of neurogenesis | Robinson and Dreher (1990) |
45 | septal nuclei - peak of neurogenesis | Finlay and Darlington (1995) |
45 | caudoputamen – peak of neurogenesis | Finlay and Darlington (1995) |
45 | nucleus accumbens - peak of neurogenesis | Finlay and Darlington (1995) |
48 | stria medullaris thalami appears | Ashwell et al. (1996) |
48 | subplate - end of neurogenesis | Robinson and Dreher (1990) |
48 | entorhinal cortex - peak of neurogenesis | Finlay and Darlington (1995) |
48 | subiculum – peak of neurogenesis | Finlay and Darlington (1995) |
48 | parasubiculum – peak of neurogenesis | Finlay and Darlington (1995) |
48 | fornix appears | Ashwell et al. (1996) |
48 | presubiculum – peak of neurogenesis | Finlay and Darlington (1995) |
48 | dentate gyrus of hippocampus - peak of neurogenesis | Finlay and Darlington (1995) |
48 | anterior commissure appears | Ashwell et al. (1996) |
48 | CA 1, CA 2 of hippocampus - peak of neurogenesis | Finlay and Darlington (1995) |
53 | neurogenesis cortical layer VI - peak (VC) of neurogenesis | Finlay and Darlington (1995) |
56 | superficial SC laminae - end of neurogenesis | Robinson and Dreher (1990) |
56 | cones - peak of neurogenesis | Finlay and Darlington (1995) |
56 | retinal amacrine cells - peak of neurogenesis | Finlay and Darlington (1995) |
57 | retinal ganglion cell generation - end of neurogenesis | Robinson and Dreher (1990) |
58.5 | neurogenesis cortical layer V - start (VC) of neurogenesis | Robinson and Dreher (1990) |
65 | neurogenesis cortical lamina VI - end (VC) of neurogenesis | Robinson and Dreher (1990) |
67 | cortical axons reach dLGN | Robinson and Dreher (1990) |
69 | optic nerve axon number - peak of neurogenesis | Robinson and Dreher (1990) |
70 | neurogenesis cortical layer V - peak (VC) of neurogenesis | Finlay and Darlington (1995) |
70 | neurogenesis cortical lamina IV - start (VC) of neurogenesis | Robinson and Dreher (1990) |
75 | neurogenesis cortical layer V - end (VC) of neurogenesis | Robinson and Dreher (1990) |
78 | LGN axons in subplate | Robinson and Dreher (1990) |
80 | neurogenesis cortical layer IV - peak (VC) of neurogenesis | Finlay and Darlington (1995) |
81.5 | cortical axons innervate dLGN | Robinson and Dreher (1990) |
85 | neurogenesis cortical layer IV - end (VC) of neurogenesis | Robinson and Dreher (1990) |
85 | rods - peak of neurogenesis | Finlay and Darlington (1995) |
85 | retinal bipolar cells - peak of neurogenesis | Finlay and Darlington (1995) |
85.5 | neurogenesis cortical layer II/III - start (VC) of neurogenesis | Rakic (1974) |
86 | superficial SC - start of lamination | Robinson and Dreher (1990) |
87 | ipsi/contra segregation in LGN and SC | Robinson and Dreher (1990) |
90 | neurogenesis cortical layer II /III - peak (VC) of neurogenesis | Finlay and Darlington (1995) |
91 | LGN axons in cortical layer IV | Robinson and Dreher (1990) |
96 | adult-like cortical innervation of dLGN | Robinson and Dreher (1990) |
96 | visual cortical axons in SC | Robinson and Dreher (1990) |
100 | neurogenesis cortical layer II/III - end (VC) of neurogenesis | Rakic (1974) |
110 | rapid axon loss in optic nerve ends | Robinson and Dreher (1990) |
123 | eye opening | Ashwell et al. (1996); Dunlop et al. (1997); Robinson and Dreher (1990) |
The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. The brain is the largest cluster of neurons in the body and is typically located in the head, usually near organs for special senses such as vision, hearing and olfaction. It is the most specialized and energy-consuming organ in the body, responsible for complex sensory perception, motor control, endocrine regulation and the development of intelligence.
A mammal is a vertebrate animal of the class Mammalia. Mammals are characterized by the presence of milk-producing mammary glands for feeding their young, a neocortex region of the brain, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors diverged in the Carboniferous Period over 300 million years ago. Around 6,400 extant species of mammals have been described and divided into 29 orders.
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Living marsupials include kangaroos, koalas, opossums, Tasmanian devils, wombats, wallabies, and bandicoots among others, while many extinct species, such as the thylacine, Thylacoleo, and Diprotodon, are also known.
Echidnas, sometimes known as spiny anteaters, are quill-covered monotremes belonging to the family Tachyglossidae, living in Australia and New Guinea. The four extant species of echidnas and the platypus are the only living mammals that lay eggs and the only surviving members of the order Monotremata. The diet of some species consists of ants and termites, but they are not closely related to the American true anteaters or to hedgehogs. Their young are called puggles.
The honey possum or noolbenger, is a tiny species of marsupial that feeds on the nectar and pollen of a diverse range of flowering plants. Found only in southwest Australia, it is an important pollinator for such plants as Banksia attenuata, Banksia coccinea and Adenanthos cuneatus.
Theria is a subclass of mammals amongst the Theriiformes. Theria includes the eutherians and the metatherians but excludes the egg-laying monotremes and various extinct mammals evolving prior to the common ancestor of placentals and marsupials.
Trichromacy or trichromatism is the possessing of three independent channels for conveying color information, derived from the three different types of cone cells in the eye. Organisms with trichromacy are called trichromats.
In the anatomy of some animals, a cloaca, pl.: cloacae, is the rear orifice that serves as the only opening for the digestive, reproductive, and urinary tracts of many vertebrate animals. All amphibians, reptiles, birds, and a few mammals, have this orifice, from which they excrete both urine and feces; this is in contrast to most placental mammals, which have two or three separate orifices for evacuation. Excretory openings with analogous purpose in some invertebrates are also sometimes called cloacae. Mating through the cloaca is called cloacal copulation and cloacal kissing.
Brain–body mass ratio, also known as the brain–body weight ratio, is the ratio of brain mass to body mass, which is hypothesized to be a rough estimate of the intelligence of an animal, although fairly inaccurate in many cases. A more complex measurement, encephalization quotient, takes into account allometric effects of widely divergent body sizes across several taxa. The raw brain-to-body mass ratio is however simpler to come by, and is still a useful tool for comparing encephalization within species or between fairly closely related species.
In neuroanatomy, the superior colliculus is a structure lying on the roof of the mammalian midbrain. In non-mammalian vertebrates, the homologous structure is known as the optic tectum, or optic lobe. The adjective form tectal is commonly used for both structures.
Encephalization quotient (EQ), encephalization level (EL), or just encephalization is a relative brain size measure that is defined as the ratio between observed and predicted brain mass for an animal of a given size, based on nonlinear regression on a range of reference species. It has been used as a proxy for intelligence and thus as a possible way of comparing the intelligence levels of different species. For this purpose, it is a more refined measurement than the raw brain-to-body mass ratio, as it takes into account allometric effects. Expressed as a formula, the relationship has been developed for mammals and may not yield relevant results when applied outside this group.
In neuroanatomy, a sulcus is a depression or groove in the cerebral cortex. It surrounds a gyrus, creating the characteristic folded appearance of the brain in humans and other mammals. The larger sulci are usually called fissures.
The commissural fibers or transverse fibers are axons that connect the two hemispheres of the brain. In contrast to commissural fibers, association fibers connect regions within the same hemisphere of the brain, and projection fibers connect each region to other parts of the brain or to the spinal cord.
The evolution of mammals has passed through many stages since the first appearance of their synapsid ancestors in the Pennsylvanian sub-period of the late Carboniferous period. By the mid-Triassic, there were many synapsid species that looked like mammals. The lineage leading to today's mammals split up in the Jurassic; synapsids from this period include Dryolestes, more closely related to extant placentals and marsupials than to monotremes, as well as Ambondro, more closely related to monotremes. Later on, the eutherian and metatherian lineages separated; the metatherians are the animals more closely related to the marsupials, while the eutherians are those more closely related to the placentals. Since Juramaia, the earliest known eutherian, lived 160 million years ago in the Jurassic, this divergence must have occurred in the same period.
Eye–hand coordination is the coordinated motor control of eye movement with hand movement and the processing of visual input to guide reaching and grasping along with the use of proprioception of the hands to guide the eyes, a modality of multisensory integration. Eye–hand coordination has been studied in activities as diverse as the movement of solid objects such as wooden blocks, archery, sporting performance, music reading, computer gaming, copy-typing, and even tea-making. It is part of the mechanisms of performing everyday tasks; in its absence, most people would not be able to carry out even the simplest of actions such as picking up a book from a table.
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Zygomaturus is an extinct genus of giant marsupial belonging to the family Diprotodontidae which inhabited Australia from the Late Miocene to Late Pleistocene.
Monotremes are mammals of the order Monotremata. They are the only group of living mammals that lay eggs, rather than bearing live young. The extant monotreme species are the platypus and the four species of echidnas. Monotremes are typified by structural differences in their brains, jaws, digestive tract, reproductive tract, and other body parts, compared to the more common mammalian types. Although they are different from almost all mammals in that they lay eggs, like all mammals, the female monotremes nurse their young with milk.
Mammalian vision is the process of mammals perceiving light, analyzing it and forming subjective sensations, on the basis of which the animal's idea of the spatial structure of the external world is formed. Responsible for this process in mammals is the visual sensory system, the foundations of which were formed at an early stage in the evolution of chordates. Its peripheral part is formed by the eyes, the intermediate - the optic nerves, and the central - the visual centers in the cerebral cortex.