Disease relevance of Fornix (Brain)

• Transection of the fimbria-fornix leads to retrograde degeneration of axotomized septal cholinergic neurons as manifested by loss of choline acetyltransferase and low-affinity nerve growth factor receptor (p75NGFR) immunoreactivity [1].

Psychiatry related information on Fornix (Brain)

• Effects of 5,7-dihydroxytryptamine injections in the fornix-fimbria on locomotor activity in photocell cages and the open field [2].
• Nicotine improvement of Morris water task performance after fimbria-fornix lesion is blocked by mecamylamine [3].

High impact information on Fornix (Brain)

• Rats receiving chronic intraventricular infusions of RTA showed significantly more low affinity NGF receptor immunoreactive (p75NGFR-IR) neurons on the lesioned side than did control animals 2 weeks following unilateral fimbria-fornix lesion [4].
• Recombinant human ciliary neurotrophic factor (CNTF) was infused for 2 weeks into the lateral ventricle of fimbria-fornix transected adult rats, and its effects were compared with those of purified mouse nerve growth factor (NGF) [5].
• To examine the mechanism by which axotomized cholinergic neurons die in vivo, lentiviral vectors expressing Bcl-xL, human nerve growth factor (hNGF), or green fluorescent protein were injected into the septum 3 weeks before transection of the fimbria fornix [6].
• We report here that NGF treatment significantly reduces both the total neuronal and cholinergic neuronal death found 2 weeks after fimbria fornix transection; there was a sparing of 50% of the neurons in the MS and essentially 100% of those in the VDB that otherwise would have died [7].
• Endogenous ciliary neurotrophic factor protects GABAergic, but not cholinergic, septohippocampal neurons following fimbria-fornix transection [8].

Chemical compound and disease context of Fornix (Brain)

• Hippocampal serotonin re-uptake and nocturnal locomotor activity after microinjections of 5,7-DHT in the fornix-fimbria [9].

Biological context of Fornix (Brain)

• Neurons in the rat medial septum (MS) and vertical limb of the diagonal band of Broca (VDB) undergo a rapid and severe cell death after transection of their dorsal projection to the hippocampus by aspiration of the ipsilateral fimbria fornix and supracallosal striae [7].
• The model is thus consistent with experimental data that show that nicotine restores gating of the N40 evoked potential in fimbria-fornix lesioned rats and of the P50 evoked potential in schizophrenic patients [10].
• Following unilateral fimbria-fornix transection, CNTFR alpha up-regulation was restricted to the MSDB ipsilateral to the lesion [11].
• We also examined whether medial septum/diagonal band neurons might die by apoptosis within two weeks of fornix fimbria lesion using terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labelling [12].
• Our findings indicate, that action potentials propagated by the fornix/fimbria to the NAc release glutamate which increases ACh release predominantly via NMDA receptors [13].

Anatomical context of Fornix (Brain)

• Because these cellular changes are reminiscent of some of the morphological abnormalities seen with glutamate receptor-mediated excitoxicity, we tested whether excitotoxic injury to the septal complex of adult rats mimics the degeneration observed within the dorsolateral septal nucleus and medial septal nucleus following fimbria-fornix transection [14].
• Some rats with fimbria-fornix lesions were implanted with acetylcholine-producing or control fibroblasts into the neocortex, another major target of the basal forebrain cholinergic system, to determine if the site of acetylcholine delivery to the damaged brain is critical for functional recovery [15].
• In rats, under halothane anesthesia, the responses evoked by fornix/fimbria stimulation in the nucleus accumbens consist of two main positive peaks (at 10 and 25 ms, referred to as P10 and P25, respectively) [16].
• No changes could be detected after atropine, handling, lateral habenula stimulation, or acute fimbria-fornix or fasciculus retroflexus transection.(ABSTRACT TRUNCATED AT 400 WORDS)[17]
• Between P14 and P21, MARCKS expression declined gradually in the hilus, remained elevated in hippocampal CA1, CA3, and granule cell layers, and increased dramatically in the corpus callosum and fimbria/fornix [18].

Associations of Fornix (Brain) with chemical compounds

• Because the fimbria fornix bundle also contains fibers other than cholinergic ones, we further evaluated the importance of the cholinergic influence by injecting pilocarpine, a muscarinic agonist [19].
• The effects of CNS axotomy on glutamate transporter and glutamate receptor expression were evaluated in adult rats following unilateral fimbria-fornix transections [20].
• Lesions of either the hippocampus (kainic acid/colchicine) or fornix-fimbria (radiofrequency current) were made before training [21].
• Similarities vs. differences in place learning and circadian activity in rats after fimbria-fornix section or ibotenate removal of hippocampal cells [22].
• Restoration of high affinity choline uptake in the hippocampal formation following septal cell suspension transplants in rats with fimbria-fornix lesions [23].

Gene context of Fornix (Brain)

• Effects of fimbria-fornix lesion and amyloid pathology on spatial learning and memory in transgenic APP+PS1 mice [24].
• Medial fimbria-fornix lesions or section of the medial corticohypothalamic tracts (MCHT) did not influence CRH mRNA levels [25].
• Results from previous studies have indicated that ciliary neurotrophic factor (CNTF) and other members of the family of gp130-associated cytokines have neuroprotective effects on septohippocampal projection neurons axotomized by fimbria-fornix transection (FFT) [26].
• Moreover, in vivo GM-CSF and EPO promoted survival of septal cholinergic neurons in adult rats which had undergone fimbria-fornix transections [27].
• Fine structure of rat septohippocampal neurons. III. Recovery of choline acetyltransferase immunoreactivity after fimbria-fornix transection [28].

Analytical, diagnostic and therapeutic context of Fornix (Brain)

• Using fimbria-fornix transection as a model, we examined whether responses of GABAergic and cholinergic septohippocampal neurons to axotomy are altered in mice lacking CNTF [8].
• PARV immunocytochemistry was performed 2, 8, 55, and 360 days after an ipsilateral entorhinal lesion and, for comparison, 10 days after an ipsilateral fimbria-fornix transection that disconnects the hippocampus from its septal and commissural afferents [29].
• Using non-radioactive in situ hybridization we investigated the effect of fimbria-fornix transection on the expression of ciliary neurotrophic factor receptor alpha (CNTFR alpha) mRNA in axotomized septohippocampal neurons of the rat septal complex [11].
• The innervation of the host dentate gyrus by graft-derived ChAT-positive fibres was unmasked by acute removal of the intrinsic septal cholinergic innervation by fimbria-fornix transection 5-7 days before perfusion [30].
• Microinjections of 5,7-dihydroxytryptamine (5,7-DHT) into the fornix-fimbria (FF) reduced dorsal hippocampal [3]5-HT uptake to 40% of control levels [2].

References