Medial forebrain bundle

Figure 7.1 Dopamine neuronal pathways. AMYG, amygdala CN, caudate nucleus MFB, medial forebrain bundle NcA, nucleus accumbers OT, olfactory tubercle PUT, putamen SN, substantia nigra. For full details see text and Moore and Bloom (1978) and Lindvall and Bjorkland (1978)...

QUESTION If you slice the medial forebrain bundle, is there a change in the resistance at the terminal area Which way does it go ... 

Fuxe 1965) and throughout the brain stem and spinal cord. A series of studies employing small intracerebral lesions (Anden et al. 1966 Ungerstedt 1971) indicated that most 5-HT nerve terminals in the forebrain arise from raphe nuclei in the midbrain and that the axons ascend through the lateral hypothalamus within the medial forebrain bundle (Moore and Heller 1967 Azmitia 1978 Conrad et al. 1974). 

An extra-bulbar olfactory pathway (EBOP) is present in teleosts and in some non-teleost genera. Olfactory fibres run within the medial forebrain bundle, and can be traced (by SBA lectin binding) beyond the olfactory bulb into areas such as the ventral telencephalon, and/or the preoptic nucleus (Hofmann and Meyer, 1995). The projection of the EBOP fibres is similar in the sturgeon, but in other non-teleosts the primary olfactory fibres reach diencephalic target nuclei. 

Consistent with these observations, there is some evidence that caffeine may act, in part, on dopaminergic fibers that project into the medial forebrain bundle. Other psychostimulants also appear to act on this system, which may be at least one of the neural mechanisms involved in the development of dependence.271 Further work has suggested a parallel between caffeine and another highly addictive drug, alcohol. Many of the same factors that enter into the development of alcoholism may also influence the development of dependence on caffeine.272... 

The detection of serotonin in nervous and non-nervous tissue was aided by the development of the Falck-Hillarp histochemical technique, a method whereby freeze-dried sections of tissue, when exposed to formaldehyde vapour cause indoleamines to emit a yellow fluorescence. Dahlstrom and Fuxe used this technique to show that the highest concentration of serotonin in the brain is located in the raphe nuclei, projections from these cell bodies ascending to the forebrain via the medial forebrain bundle. Descending fibres were also shown to project to the dorsal and lateral horns and the intermediolateral column of the spinal cord. Detailed observation of the distribution of the serotonergic system in the brain became possible with... 

Willick, Myma L, and tarry Kokkinidis. 1995. "The Effects of Ventral Tegmental Administration of GABAa, GABA and NMDA Receptor Agonists on Medial Forebrain Bundle Self-Stimulation." Behavioural Brain Research 70 31-36. 

Woodward, Albert, Joan Epstein, Joseph Gfroerer, Daniel Melnick, Richard Thoreson, and Douglas Wilson. 1997. "The Drug Abuse Treatment Gap Recent Estimates." Health Care Financing Review 18 5-17-Yeomans, John S. 1989. "Two Substrates for Medial Forebrain Bundle Self-Stimulation Myelinated Axons and Dopamine Axons." Neuroscience and Biobehavioral Reviews 13 91-98. 

Snowhill EW, Wamsley JK. Serotonin type-2 receptors undergo axonal transport in the medial forebrain bundle. Eur J Pharmacol 1983 95 325-327. 

Veening JG, Swanson LW, Cowan WM, Nieuwenhuys R, Geeraedts LMG (1982) The medial forebrain bundle of the rat. II. An autoradiographic study of the topography of the major descending and ascending... 

Young SD, Michael AC (1993) Voltammetry of extracellular dopamine in rat striatum during ICSS-like electrical stimulation of the medial forebrain bundle. Brain Res 500 305-307. 

Fig. 2. A. Forebrain dopamine projection system in rodents and primates. The nigrostriatal pathway projects from the A8 and A9 groups of the substantia nigra (SN) via the medial forebrain bundle (mfb) to the neostriatum (NS). The mesocorticolimbic pathway projects from the more medially located A10 cell group of the ventral tegmental area (VTA) to the nucleus accumbens (NAcc) and olfactory tubercle (OT) of the ventral striatum (VS) and limbic forebrain areas including prefrontal cortex (Ctx), septum (Se) and amygdala (A). B. Striatal projection areas in the rodent brain are divided into the more dorsal neostriatum, and ventral striatum. C. In the primate brain, including human and illustrated for the marmoset, the neostriatum is divided by the fibers of the internal capsule into caudate nucleus (CN) and putamen (Pu). Correspondingly, the neostriatum of rats is sometimes designated the caudate-putamen (CPu) complex.

Smith AD, Amalric M, Koob GF, Zigmond MJ (2002) Effect of bilateral 6-hydroxydopamine lesions of the medial forebrain bundle on reaction time. Neuropsychopharmacology 26 756-164. 

Tseng JL, Baetge EE, Zum AD, Aebischer P (1997) GDNF reduces drug induced rotadonal behavior after medial forebrain bundle d ansacdon by a mechanism not involving striatal dopamine. J Neurosci 17 325—333. 

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