Effects of blinding and pinealectomy on regional brain monoamine concentrations

Transcranial AC pulsed applications of weak electromagnetic fields reduces freezing and falling in progressive supranuclear palsy: a case report

Freezing is a common and disabling symptom in patients with Parkinsonism. It affects most commonly the gait in the form of start hesitation and sudden immobility often resulting in falling. A higher incidence of freezing occurs in patients with progressive supranuclear palsy (PSP) which is characterized clinically by a constellation of symptoms including supranuclear ophthalmoplegia, postural instability, axial rigidity, dysarthria, Parkinsonism, and pseudobulbar palsy. Pharmacologic therapy of PSP is currently disappointing and the disease progresses relentlessly to a fatal outcome within the first decade after onset. This report concerns a 67 year old woman with a diagnosis of PSP in whom freezing and frequent falling were the most disabling symptoms of the disease at the time of presentation. Both symptoms, which were rated 4 on the Unified Parkinson Rating Scale (UPRS) which grades Parkinsonian symptoms and signs from 0 to 4, with 0 being normal and 4 being severe symptoms, were resistant to treatment with dopaminergic drugs such as levodopa, amantadine, selegiline and pergolide mesylate as well as with the potent and highly selective noradrenergic reuptake inhibitor nortriptyline. Weekly transcranial applications of AC pulsed electromagnetic fields (EMFs) of picotesla flux density was associated with approximately 50% reduction in the frequency of freezing and about 80-90% reduction in frequency of falling after a 6 months follow-up period. At this point freezing was rated 2 while falling received a score of 1 on the UPRS. In addition, this treatment was associated with an improvement in Parkinsonian and pseudobulbar symptoms with the difference between the pre-and post EMF treatment across 13 measures being highly significant (p < .005; Sign test). These results suggest that transcranial administration AC pulsed EMFs in the picotesla flux density is efficacious in the treatment of PSP.

Magnetic fields in the treatment of Parkinson's disease

Levodopa-induced dyskinesias are a common complication of chronic dopaminergic therapy in patients with Parkinson's disease (PD). The overall prevalence of levodopa-induced dyskinesias ranges from 40%-90% and is related to the underlying disease process, pharmacologic factors, and to the duration of high dose levodopa therapy. The mechanisms underlying the emergence of levodopa-induced dyskinesias are unknown, although most investigators favor the theory that striatal dopamine receptor supersensitivity is directly responsible for the development of these abnormal movements. In laboratory animals, the pineal hormone melatonin has been shown to regulate striatal dopaminergic activity and block levodopa-induced dyskinesias (Cotzias et al., 1971). Since the pineal gland is known to be a magnetosensitive organ and as application of external magnetic fields has been shown to alter melatonin secretion, we studied the effects of application of external artificial weak magnetic fields in a Parkinsonian patient with severe levodopa-induced dyskinesias ("on-off"). Application of weak magnetic fields with a frequency of 2 Hz and intensity of 7.5 picotesla (pT) for a 6 minute period resulted in a rapid and dramatic attenuation of Parkinsonian disability and an almost complete resolution of the dyskinesias. This effect persisted for about 72 hours after which the patient regressed to his pretreatment state. To ascertain if the responses elicited in the laboratory were reproducible, the patient was instructed to apply magnetic fields of the same characteristics daily at home. These subsequent treatments paralleled the initial response with a sustained improvement being maintained during an observation period lasting at least one month. This case demonstrates the efficacy of weak magnetic fields in the treatment of Parkinsonism and motor complications of chronic levodopa therapy.

Differential effects of pinealectomy on amygdala and hippocampus serotonin metabolism

The purpose of the present study was to determine the effects of long-term pinealectomy on serotonin metabolism in the amygdala and the hippocampus of male rats. Pinealectomy did not significantly alter either tryptophan or serotonin concentrations in the amygdala or the hippocampus. However, statistically significant decreases in 5-hydroxyindole-3-acetic acid levels and tryptophan hydroxylase activity were found in the amygdala. Monoamine oxidase activity was unchanged in both regions. These results support the involvement of the amygdaloid serotoninergic system in mediating the functions of the pineal gland.

Binding characteristics, regional distribution and diurnal variation of [125I]-iodomelatonin binding sites in the chicken brain

The [125I]-iodomelatonin binding sites in chicken brain membrane preparations were studied. The binding of [125I]-iodomelatonin to the membrane preparations of chicken brain was rapid, stable, saturable, and reversible. The order of pharmacological affinities of [125I]-iodomelatonin binding sites in the chicken brain membrane preparations was: melatonin greater than 6-chloromelatonin greater than N-acetylserotonin greater than 5-hydroxytryptamine greater than tryptamine greater than 5-methoxytryptophol, much greater than 1-acetylindole-3-carboxaldehyde, 5-hydroxyindole-3-acetic acid, L-tryptophan, 5-hydroxytryptophan, 3-acetylindole. Compounds known to act on the receptor of norepinephrine or acetylcholine were inactive as compared to melatonin. Among the various brain regions studied, melatonin binding had maximal level in the hypothalamus, intermediate levels in the mid-brain, ponsmedulla, and telencephalon, and minimum level in the cerebellum. Subcellular fraction studies indicated that 40% of the binding was located in the mitochondrial fraction, 27% in the nuclear, 26% in the microsomal, and 6% in the cytosol fraction. Scatchard analysis of the membrane preparations revealed a dissociation constant (Kd) of 199.6 +/- 17 pM and a total number of binding sites (Bmax) of 16.6 +/- 0.75 fmol/mg protein at midlight. Thus, our results showed the presence of specific melatonin binding sites in the chicken brain membrane preparations. Saturation studies demonstrated that [125I]-iodomelatonin binding capacity in chicken brain membrane preparations were 40% greater at midlight (16.6 +/- 0.75 fmol/mg protein) than at middark (10.6 +/- 0.56 fmol/mg protein), with no significant variation in their binding affinities.

Changes with darkness in regional brain 5-hydroxytryptamine and 5-hydroxyindole acetic acid: local differences with pinealectomy, sham surgery, and melatonin

Brain regional 5-HT (5-hydroxytryptamine) and 5-HIAA (5-hydroxyindole-3-acetic acid) concentrations in male LE rats at three times were measured by a fluorescence method, to evaluate effects of intracranial surgery and administration of melatonin on the changes in these compounds during the first part of the dark phase of the daily cycle in a fixed 12:12 L:D photoperiod. Early surgical pinealectomy or a similar but sham intracranial surgery, led to delay in darkness-associated fall in frontal cortical and striatal 5-HT. A single melatonin injection two hours before darkness, reversed this effect in frontal cortex but not striatum. Melatonin's specification of action in this experiment is interpreted as residing in specific timing of release and/or administration, rather than in either a fixed or general basis neurochemically.

Pineal indoles: significance and measurement

Despite intensive investigation, particularly over the past fifteen years, many aspects of pineal function with respect to mammalian physiology remain obscure. Much of this work is reviewed and particular attention focussed on indole metabolism within the pineal gland. Emphasis is placed on the development of new analytical techniques with special reference to high performance liquid chromatography coupled with electrochemical detection. The growth in knowledge regarding pineal indole synthesis which can be attributed to the use of this technique is discussed. The possibility that pineal indoles other than melatonin may function as hormones or neuromodulators is considered. A functional role for 5-hydroxytryptophol as a neuromodulator, possibly associated with diffuse neuroendocrine function (amine precursor, uptake and decarboxylation, APUD) is suggested.

Catecholamines and serotonin in the rat central nervous system after 6-OHDA, 5-7-DHT and p-CPA

The norepinephrine (NE), epinephrine (EPI), dopamine (DA) and serotonin (5-HT) contents were measured radioenzymatically in seven anatomically defined regions (frontal cerebral cortex, hippocampus, hypothalamus, midbrain, pons-medulla oblongata, cerebellum and spinal cord) in adult normal animals, after treatment with the tryptophan hydroxylase inhibitor p-chlorophenylalanine (p-CPA), and after the intraventricular administration of either 6-hydroxydopamine (6-OHDA) or 5,7-dihydroxytryptamine (5,7-DHT). The effects of p-CPA seemed not restricted to 5-HT, since reductions in catecholamine (CA) content were detected in several regions. After 5,7-DHT given under desimipramine (DMI) protection, comparable reductions in 5-HT levels were obtained but the changes in CA were less severe than after p-CPA. The neurotoxin 6-OHDA decreased the CA in all regions but also 5-HT content in hippocampus, hypothalamus and pons-medulla. The significance and the interpretation of these changes are discussed in relation to the specificity of the drugs employed, together with an assessment of the local monoamine turnover and the possible functional effects of monoamine interactions in the CNS.