A Method for Chronically Implanting Stimulating Electrodes into the Brains of Locusts, and some Results of Stimulation

1963 ◽  
Vol 40 (2) ◽  
pp. 271-284
Author(s):  
C. H. FRASER ROWELL
Keyword(s):  
Stainless Steel ◽  
Brain Stimulation ◽  
Sexual Behaviour ◽  
Foraging Behaviour ◽  
Stimulating Electrodes ◽  
The Brain ◽  
Antennal Movement ◽  
Steel Electrodes

1. Methods are described for implanting permanent stainless-steel electrodes into the brains of locusts, for stimulating the brain under near-normal conditions, and for localizing the electrode subsequently. 2. Threshold currents measured under these conditions are lower than those required in acute preparations, or if the animal is restrained. 3. The results of stimulation are described for four common aspects of behaviour. These are antennal movement, locomotion, feeding and sexual behaviour. 4. The effect of stimulation on antennal and locomotory movements largely confirms previous work on crickets. 5. Feeding and foraging behaviour, which is a very common result, is shown to be almost completely determined by peripheral stimuli at the time of brain stimulation. The role of the latter is permissive or disinhibitory rather than causal or excitatory. 6. Integrated sexual behaviour is occasionally inhibited, but never elicited, by stimulation. This contrasts with observations on crickets, and its implications are discussed.

scholarly journals The Role of Melatonin and Bromocriptine in the Regulation of Prolactin Secretion in Animals – A Review

2015 ◽  
Vol 15 (4) ◽  
pp. 849-860 ◽  
Author(s):  
Edyta Molik ◽  
Michał Błasiak
Keyword(s):  
Sexual Behaviour ◽  
Receptor Agonist ◽  
D2 Receptor ◽  
Prolactin Secretion ◽  
D2 Receptors ◽  
Day Length ◽  
Maternal Instinct ◽  
D2 Receptor Agonist ◽  
The Brain

Abstract Changes in the concentration of melatonin and prolactin are associated with response to day length. The factors that stimulate the release of PRL include, among others, TRH, VIP, endorphins, oestrogen, and adrenaline. PRL secretion inhibitors include DA, GABA, progesterone and bromocriptine (exogenous compound), used in the treatment of hyperprolactinemia D2 receptor agonist. The biological activity of this compound is to stimulate dopamine D2 receptors in the pituitary, which inhibits PRL secretion via the tuberoinfundibular pathway (Fitzgerald and Dinan, 2008). In sheep treated with bromocriptine there is a decrease in PRL concentration and an increase in the sensitivity of cells producing LH to GnRH, but there is no disturbance in the course of the estrous cycle. Rams show decreased libido and changes in sexual behaviour. The administration of bromocriptine throughout the period of sexual activity and the period of rearing offspring affects maternal instinct, which involves the inhibition of PRL secretion. It is not clarified whether the effect of bromocriptine on sexual behaviour is associated with its direct impact on behavioural centres in the brain, or indirectly through the regulation of PRL secretion. However, the seasonal variations in the effects of bromocriptine on sexual behaviour can strengthen the hypothesis that the effect of bromocriptine on sexual development behaviour is associated with changes in the intensity of PRL secretion rather than by the inhibition of behavioural bromocriptine brain centres. The process of regulation of prolactin secretion by bromocriptine requires further examination.

scholarly journals Oestradiol and prostaglandin F2α regulate sexual displays in females of a sex-role reversed fish

2014 ◽  
Vol 281 (1778) ◽  
pp. 20133070 ◽  
Author(s):  
David Gonçalves ◽  
Silvia Santos Costa ◽  
Magda C. Teles ◽  
Helena Silva ◽  
Mafalda Inglês ◽  
...  
Keyword(s):  
Sexual Behaviour ◽  
Sex Steroids ◽  
Sex Role ◽  
Significant Proportion ◽  
Prostaglandin F2α ◽  
Sexual Behaviours ◽  
Salaria Pavo ◽  
The Brain ◽  
Positive Effect

The mechanisms regulating sexual behaviours in female vertebrates are still poorly understood, mainly because in most species sexual displays in females are more subtle and less frequent than displays in males. In a sex-role reversed population of a teleost fish, the peacock blenny Salaria pavo , an external fertilizer, females are the courting sex and their sexual displays are conspicuous and unambiguous. We took advantage of this to investigate the role of ovarian-synthesized hormones in the induction of sexual displays in females. In particular, the effects of the sex steroids oestradiol (E2) and testosterone (T) and of the prostaglandin F2α (PGF2α) were tested. Females were ovariectomized and their sexual behaviour tested 7 days (sex steroids and PGF2α) and 14 days (sex steroids) after ovariectomy by presenting females to an established nesting male. Ovariectomy reduced the expression of sexual behaviours, although a significant proportion of females still courted the male 14 days after the ovary removal. Administration of PGF2α to ovariectomized females recovered the frequency of approaches to the male's nest and of courtship displays towards the nesting male. However, E2 also had a positive effect on sexual behaviour, particularly on the frequency of approaches to the male's nest. T administration failed to recover sexual behaviours in ovariectomized females. These results suggest that the increase in E2 levels postulated to occur during the breeding season facilitates female mate-searching and assessment behaviours, whereas PGF2α acts as a short-latency endogenous signal informing the brain that oocytes are mature and ready to be spawned. In the light of these results, the classical view for female fishes, that sex steroids maintain sexual behaviour in internal fertilizers and that prostaglandins activate spawning behaviours in external fertilizers, needs to be reviewed.

The Role of the Parietal Cortex in Multisensory and Response Integration: Evidence from Transcranial Direct Current Stimulation (tDCS)

2014 ◽  
Vol 27 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Sharon Zmigrod
Keyword(s):  
Multisensory Integration ◽  
Parietal Cortex ◽  
Direct Current ◽  
Brain Stimulation ◽  
Transcranial Direct Current Stimulation ◽  
Brain Regions ◽  
The Right ◽  
The Brain ◽  
Healthy Participants

The question of how the brain forms unified representations from multisensory data that are processed in distinct cortical regions is known in the literature as ‘the binding problem’. In the last decade, several studies have suggested possible neural mechanisms and brain regions that might be involved in integration processes. One of the brain regions that is implicated with multisensory perception is the posterior parietal cortex (PPC). Evidence from patients with parietal lesions suggests the involvement of the PPC in coherent perception. Here, we investigated the role of the PPC in multisensory feature integration through experimental manipulation of non-invasive brain stimulation with healthy participants using transcranial direct current stimulation (tDCS). In different sessions, healthy participants received anodal, cathodal, or sham stimulation (2 mA, 20 min) over the right PPC while performing an audio-visual event-file task. The results underscore two interesting observations. Firstly, there was a significant difference in integration effects between features from different modalities in the anodal stimulation compared to sham, suggesting interference of the multisensory integration processes during the brain stimulation. And secondly, after anodal stimulation, the unattended feature became more likely to be integrated with the response feature compared to the other conditions, presumably through an interference of attentional processes. Hence, these findings emphasize the role of the right PPC in multisensory integration. Furthermore, from a methodological perspective, tDCS can be used as an experimental tool by creating a temporary, reversible disruption in cognitive processes in order to explore the mechanisms underlying cognitive functions.

scholarly journals Brain Circuits Involved in the Development of Chronic Musculoskeletal Pain: Evidence From Non-invasive Brain Stimulation

2021 ◽  
Vol 12 ◽  
Author(s):  
Mina Kandić ◽  
Vera Moliadze ◽  
Jamila Andoh ◽  
Herta Flor ◽  
Frauke Nees
Keyword(s):  
Chronic Pain ◽  
Musculoskeletal Pain ◽  
Brain Stimulation ◽  
Brain Regions ◽  
Mechanistic Models ◽  
Imaging Studies ◽  
Non Invasive ◽  
Brain Circuits ◽  
The Brain

It has been well-documented that the brain changes in states of chronic pain. Less is known about changes in the brain that predict the transition from acute to chronic pain. Evidence from neuroimaging studies suggests a shift from brain regions involved in nociceptive processing to corticostriatal brain regions that are instrumental in the processing of reward and emotional learning in the transition to the chronic state. In addition, dysfunction in descending pain modulatory circuits encompassing the periaqueductal gray and the rostral anterior cingulate cortex may also be a key risk factor for pain chronicity. Although longitudinal imaging studies have revealed potential predictors of pain chronicity, their causal role has not yet been determined. Here we review evidence from studies that involve non-invasive brain stimulation to elucidate to what extent they may help to elucidate the brain circuits involved in pain chronicity. Especially, we focus on studies using non-invasive brain stimulation techniques [e.g., transcranial magnetic stimulation (TMS), particularly its repetitive form (rTMS), transcranial alternating current stimulation (tACS), and transcranial direct current stimulation (tDCS)] in the context of musculoskeletal pain chronicity. We focus on the role of the motor cortex because of its known contribution to sensory components of pain via thalamic inhibition, and the role of the dorsolateral prefrontal cortex because of its role on cognitive and affective processing of pain. We will also discuss findings from studies using experimentally induced prolonged pain and studies implicating the DLPFC, which may shed light on the earliest transition phase to chronicity. We propose that combined brain stimulation and imaging studies might further advance mechanistic models of the chronicity process and involved brain circuits. Implications and challenges for translating the research on mechanistic models of the development of chronic pain to clinical practice will also be addressed.

Are catechol oestrogens obligatory mediators of oestrogen action in the central nervous system? II. Potencies of natural and synthetic oestrogens for induction of gonadotrophin release and female sexual behaviour in the rat

1986 ◽  
Vol 110 (3) ◽  
pp. 499-505 ◽  
Author(s):  
N. J. MacLusky ◽  
L. C. Krey ◽  
B. Parsons ◽  
G. R. Merriam ◽  
D. L. Loriaux ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Sexual Behaviour ◽  
Female Rats ◽  
Oestrogen Receptors ◽  
Ability To Act ◽  
The Central Nervous System ◽  
Lh Release ◽  
Lh Secretion ◽  
The Brain

ABSTRACT The role of catechol oestrogen formation in the mechanism by which circulating oestrogens facilitate gonadotrophin release and female sexual behaviour was explored in adult female rats. The effects of oestradiol-17β were compared with those of a group of oestrogens with either a reduced affinity for oestrogen receptors (oestradiol-17α) or a reduced ability to act as substrates for catechol oestrogen formation (2-fluoro-oestradiol, 4-fluoro-oestradiol and moxestrol (11β-methoxy-17α-ethynyloestradiol)). Rats were ovariectomized on the evening of dioestrus day 1 of the 4-day oestrous cycle and implanted s.c. 12 h later with infusion pumps containing either one of the test oestrogens or vehicle alone. Infusion rates for oestradiol-17β, moxestrol, 2-fluoro-oestradiol and 4-fluoro-oestradiol were adjusted to give concentrations of nuclear oestrogen receptors in the brain and pituitary gland within the range of those found in intact female rats during pro-oestrus. Oestradiol-17α was infused at the same and at a tenfold higher rate than that of oestradiol-17β; neither of these treatments with oestradiol-17α significantly increased brain or pituitary gland nuclear oestrogen receptor levels. On the day after the pump was implanted, samples of tail vein blood were withdrawn at 12.00, 14.00, 16.00 and 18.00 h for LH assay. All animals were then injected s.c. with 1 mg progesterone in propylene glycol, and tested for feminine sexual behaviour 5 h later. Oestradiol-17β, moxestrol, 2-fluoro-oestradiol and 4-fluoro-oestradiol all elicited pronounced LH surges and facilitated progesterone-triggered proceptive and lordosis behaviours. In contrast, oestradiol-17α was without effect on LH secretion and sexual behaviours. These results are consistent with the hypothesis that catechol oestrogen biosynthesis is not an obligatory step in the mechanism by which circulating oestrogens induce LH release and feminine sexual behaviour in the rat. J. Endocr. (1986) 110, 499–505

The Role of Mitochondria in the Genesis of Neuroaxonal Dystrophy in the Brains of Aging Mice

1975 ◽  
Vol 33 ◽  
pp. 372-373
Author(s):  
J.E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Present Report ◽  
Light And Electron Microscopy ◽  
Dorsal Column ◽  
Neuroaxonal Dystrophy ◽  
Nucleus Gracilis ◽  
Dystrophic Axons ◽  
The Brain ◽  
Nucleus Cuneatus

Although neuroaxonal dystrophy (NAD) has been examined by light and electron microscopy for years, the nature of the components in the dystrophic axons is not well understood. The present report examines nucleus gracilis and cuneatus (the dorsal column nuclei) in the brain stem of aging mice.Mice (C57BL/6J) were sacrificed by aldehyde perfusion at ages ranging from 3 months to 23 months. Several brain areas and parts of other organs were processed for electron microscopy.At 3 months of age, very little evidence of NAD can be discerned by light microscopy. At the EM level, a few axons are found to contain dystrophic material. By 23 months of age, the entire nucleus gracilis is filled with dystrophic axons. Much less NAD is seen in nucleus cuneatus by comparison. The most recurrent pattern of NAD is an enlarged profile, in the center of which is a mass of reticulated material (reticulated portion; or RP).

Fibrinolytic Activity of Cerebro-Spinal Fluid and the Development of Artificial Cerebral Haematomas in Dogs

1969 ◽  
Vol 21 (02) ◽  
pp. 294-303 ◽  
Author(s):  
H Mihara ◽  
T Fujii ◽  
S Okamoto
Keyword(s):  
Cerebrospinal Fluid ◽  
Carboxylic Acid ◽  
Fibrinolytic Activity ◽  
Clinical Implications ◽  
Trans Form ◽  
Plate Method ◽  
Blood Samples ◽  
Fibrin Plate ◽  
The Brain

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.

Neuromyelitis optica spectrum: novel concept of pathogenesis, diagnosis and treatment of Devic’s disease

2009 ◽  
Vol 150 (46) ◽  
pp. 2101-2109 ◽  
Author(s):  
Péter Csécsei ◽  
Anita Trauninger ◽  
Sámuel Komoly ◽  
Zsolt Illés
Keyword(s):  
Neuromyelitis Optica ◽  
Water Channel ◽  
Diagnostic Procedures ◽  
Diagnosis And Treatment ◽  
Clinical Settings ◽  
Permanent Disability ◽  
Therapeutic Decisions ◽  
Novel Concept ◽  
The Brain

The identification of autoantibodies generated against the brain isoform water channel aquaporin4 in the sera of patients, changed the current diagnostic guidelines and concept of neuromyelitis optica (NMO). In a number of cases, clinical manifestation is spatially limited to myelitis or relapsing optic neuritis creating a diverse. NMO spectrum. Since prevention of relapses provides the only possibility to reduce permanent disability, early diagnosis and treatment is mandatory. In the present study, we discuss the potential role of neuroimaging and laboratory tests in differentiating the NMO spectrum from other diseases, as well as the diagnostic procedures and therapeutic options. We also present clinical cases, to provide examples of different clinical settings, diagnostic procedures and therapeutic decisions.

Sign in / Sign up

Export Citation Format

Share Document