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Lateral Horn Of Insect Brain
The lateral horn (lateral protocerebrum) is one of the two areas of the insect brain where projection neurons of the antennal lobe send their axons. The other area is the mushroom body. Several morphological classes of neurons in the lateral horn receive olfactory information through the projection neurons. In lateral horn, axons of pheromone-sensitive projection neurons are segregated from the axons of plant odor-sensitive projection neurons. In addition, the dendrites of lateral horn neurons are restricted to one of these two zones, suggesting that pheromones and plant odors are processed separately in the lateral horn. Lateral horn neurons responsive to non-pheromonal odors arborize widely in the lateral horn, possibly integrating information from a large number of projection neurons (even if the projection neurons themselves project only to specific regions of the lateral horn). Intracellular recordings from lateral horn neurons show that many of these neurons respond broadly to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocerebrum
The protocerebrum is the first segment of the panarthropod brain. Recent studies suggest that it comprises two regions. Region associated with the expression of ''six3'' ''six3'' is a transcription factor that marks the anteriormost part of the developing body in a whole host of Metazoa. In the panarthropod brain, the anteriormost (rostralmost) part of the germband expresses six3. This region is described as medial, and corresponds to the annelid prostomium. In arthropods, it contains the ''pars intercerebralis'' and ''pars lateralis''. ''six3'' is associated with the euarthropod labrum and the onychophoran frontal appendages (antennae). Region associated with the expression of ''orthodenticle'' The other region expresses homologues of orthodenticle, ''Otx'' or ''otd''. This region is more caudal and lateral, and bears the eyes. Orthodenticle is associated with the protocerebral bridge, part of the central complex, traditionally a marker of the prosocerebrum. In th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Olfaction
Insect olfaction refers to the function of chemical receptors that enable insects to detect and identify volatile compounds for foraging, predator avoidance, finding mating partners (via pheromones) and locating oviposition habitats. Thus, it is the most important sensation for insects. Most important insect behaviors must be timed perfectly which is dependent on what they smell and when they smell it. For example, olfaction is essential for locating host plants and hunting prey in many species of insects, such as the moth '' Deilephila elpenor'' and the wasp ''Polybia sericea'', respectively. The two organs insects primarily use for detecting odors are the antennae and specialized mouth parts called the maxillary palps. However, a recent study has demonstrated the olfactory role of ovipositor in fig wasps. Inside of these olfactory organs there are neurons called olfactory receptor neurons which, as the name implies, house receptors for scent molecules in their cell membrane. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kenyon Cell
Kenyon cells are the intrinsic neurons of the mushroom body, a neuropil found in the brains of most arthropods and some annelids. They were first described by F. C. Kenyon in 1896. The number of Kenyon cells in an organism varies greatly between species. For example, in the fruit fly, ''Drosophila melanogaster,'' there are about 2,500 Kenyon cells per mushroom body, while in cockroaches there are about 230,000. Structure While the exact features of Kenyon cells can vary between species, there are enough similarities to define their general structure. Kenyon cells have dendritic branches that arborize in the calyx or calyces, cup-shaped regions of the mushroom body. At the base of the calyces, Kenyon cell axons come together and form a bundle known as the pedunculus. At the end of the pedunculus, Kenyon cell axons bifurcate and extend branches into the vertical and medial lobes. Kenyon cells are mainly postsynaptic in the calyces, where their synapses form microglomeruli. These mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mushroom Bodies
The mushroom bodies or ''corpora pedunculata'' are a pair of structures in the brain of insects, other arthropods, and some annelids (notably the ragworm ''Platynereis dumerilii''). They are known to play a role in olfactory learning and memory. In most insects, the mushroom bodies and the lateral horn are the two higher brain regions that receive olfactory information from the antennal lobe via projection neurons. They were first identified and described by French biologist Félix Dujardin in 1850. Structure Mushroom bodies are usually described as neuropils, i.e. as dense networks of neuronal processes (dendrite and axon terminals) and glia. They get their name from their roughly hemispherical ''calyx'', a protuberance that is joined to the rest of the brain by a central nerve tract or ''peduncle''. Most of our current knowledge of mushroom bodies comes from studies of a few species of insect, especially the cockroach ''Periplaneta americana'', the honey bee ''Apis mellifera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mushroom Bodies
The mushroom bodies or ''corpora pedunculata'' are a pair of structures in the brain of insects, other arthropods, and some annelids (notably the ragworm ''Platynereis dumerilii''). They are known to play a role in olfactory learning and memory. In most insects, the mushroom bodies and the lateral horn are the two higher brain regions that receive olfactory information from the antennal lobe via projection neurons. They were first identified and described by French biologist Félix Dujardin in 1850. Structure Mushroom bodies are usually described as neuropils, i.e. as dense networks of neuronal processes (dendrite and axon terminals) and glia. They get their name from their roughly hemispherical ''calyx'', a protuberance that is joined to the rest of the brain by a central nerve tract or ''peduncle''. Most of our current knowledge of mushroom bodies comes from studies of a few species of insect, especially the cockroach ''Periplaneta americana'', the honey bee ''Apis mellifera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Action Potential
An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and in some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells. In neurons, action potentials play a central role in cell-cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses, or to motor cells or glands. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of events l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projection Neuron
The projection fibers consist of efferent and afferent fibers uniting the cortex with the lower parts of the brain and with the spinal cord. In human neuroanatomy, bundles of axons (nerve fibers) called tracts, within the brain, can be categorized by their function into association fibers, projection fibers, and commissural fibers. In the neocortex, projection neurons are excitatory neurons that send axons to distant brain targets. Considering the six histologically-distinct layers of the neocortex, ''associative projection neurons'' extend axons within one cortical hemisphere; ''commissural projection neurons'' extend axons across the midline to the contralateral hemisphere; and ''corticofugal projection neurons'' extend axons away from the cortex. That said, some neurons are multi-functional and can therefore be categorized into more than one such category. Efferent The principal efferent fibers are: * (1) the motor tract, occupying the genu and anterior two-thirds of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interneuron
Interneurons (also called internuncial neurons, relay neurons, association neurons, connector neurons, intermediate neurons or local circuit neurons) are neurons that connect two brain regions, i.e. not direct motor neurons or sensory neurons. Interneurons are the central nodes of neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They play vital roles in reflexes, neuronal oscillations, and neurogenesis in the adult mammalian brain. Interneurons can be further broken down into two groups: local interneurons and relay interneurons. Local interneurons have short axons and form circuits with nearby neurons to analyze small pieces of information. Relay interneurons have long axons and connect circuits of neurons in one region of the brain with those in other regions. However, interneurons are generally considered to operate mainly within local brain areas. The interaction between interneurons allow the brain to perform c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instinct
Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing both innate (inborn) and learned elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a very short to medium length sequence of actions, without variation, are carried out in response to a corresponding clearly defined stimulus. Any behaviour is instinctive if it is performed without being based upon prior experience (that is, in the absence of learning), and is therefore an expression of innate biological factors. Sea turtles, newly hatched on a beach, will instinctively move toward the ocean. A marsupial climbs into its mother's pouch upon being born. Other examples include animal fighting, animal courtship behaviour, internal escape functions, and the building of nests. Though an instinct is defined by its invariant innate characteristics, details of its performance can be changed by experience; for example, a dog can imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antennal Lobe
The antennal lobe is the primary (first order) olfactory brain area in insects. The antennal lobe is a sphere-shaped deutocerebral neuropil in the brain that receives input from the olfactory sensory neurons in the antennae and mouthparts. Functionally, it shares some similarities with the olfactory bulb in vertebrates. The anatomy and physiology function of the insect brain can be studied by dissecting open the insect brain and imaging or carrying ou''in vivo'' electrophysiological recordingsfrom it. Structure In insects, the olfactory pathway starts at the antennae (though in some insects like ''Drosophila'' there are olfactory sensory neurons in other parts of the body) from where the sensory neurons carry the information about the odorant molecules impinging on the antenna to the antennal lobe. The antennal lobe is composed of densely packed neuropils, termed glomeruli, where the sensory neurons synapse with the two other kinds of neurons, the postsynaptic principle neurons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Brain
The supraesophageal ganglion (also "supraoesophageal ganglion", "arthropod brain" or "microbrain") is the first part of the arthropod, especially insect, central nervous system. It receives and processes information from the first, second, and third Metamerism (biology), metameres. The supraesophageal ganglion lies Dorsum (anatomy), dorsal to the esophagus and consists of three parts, each a pair of ganglia that may be more or less pronounced, reduced, or fused depending on the genus (biology), genus: * The ''protocerebrum'', associated with the arthropod eye, eyes (Eye#Compound eyes, compound eyes and ocelli). Directly associated with the eyes is the optic lobe (arthropod), optic lobe, as the visual center of the brain. * The ''deutocerebrum'' processes sensory information from the Antenna (biology), antennae. It consists of two parts, the antennal lobe and the dorsal lobe. The dorsal lobe also contains motor neurons which control the antennal muscles. * The ''tritocerebrum'' in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxilla (arthropod Mouthpart)
In arthropods, the maxillae (singular maxilla) are paired structures present on the head as mouthparts in members of the clade Mandibulata, used for tasting and manipulating food. Embryologically, the maxillae are derived from the 4th and 5th segment of the head and the maxillary palps; segmented appendages extending from the base of the maxilla represent the former leg of those respective segments. In most cases, two pairs of maxillae are present and in different arthropod groups the two pairs of maxillae have been variously modified. In crustaceans, the first pair are called maxillulae (singular maxillula). Modified coxae at the base of the pedipalps in spiders are also called "maxillae", although they are not homologous with mandibulate maxillae. Myriapoda Millipedes In millipedes, the second maxillae have been lost, reducing the mouthparts to only the first maxillae which have fused together to form a gnathochilarium, acting as a lower lip to the buccal cavity and the man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
