Cultivation of Chlorella vulgaris in Column Photobioreactor for Biomass Production and Lipid Accumulation.

Microalgae have been used as energy resources in recent decades to mitigate the global energy crisis. As the demand for pure microalgae strains for commercial use increases, designing an effective photobioreactor (PBR) for mass cultivation is important. Chlorella vulgaris, a local freshwater microalga, was used to study the algal biomass cultivation and lipid production using various PBR configurations (bubbling, air-lift, porous air-lift). The results show that a bubbling column design is a better choice for the cultivation of Chlorella vulgaris than an air-lift one. The highest biomass concentration in the bubbling PBR was 0.78 g/L while the air-lift PBR had a value of 0.09 g/L. Key operating parameters, including draft-tube length and bubbling flowrate, were then optimized based on biomass production and lipid yield. The highest lipid content was in the porous air-lift PBR and the air-lift PBR with shorter draft tube (35 cm) was also better than a longer one (50 cm) for algal cultivation, but the microalgae attachment on the inner tube of PBR always occurred. The highest biomass concentration could be produced under the highest gas flowrate of 2.7 L/min, whereas the lowest dry cell mass was under the lowest gas flowrate of 0.2 L/min.

Scenedesmus quadricauda for Nutrient Removal and Lipid Production in Wastewater.

Scenedesmus quadricauda, a local freshwater microalga, was used to treat primary settled and filtrate wastewater and to produce algal lipid. For the primary settled wastewater, the maximum biomass concentrations of acclimated and unacclimated microalgae were 0.995 g/L and 0.940 g/L, respectively. Over 90% orthophosphate and 95% ammonia nitrogen in the acclimated and unacclimated cultures, respectively, were removed after five days. The lipid contents of the microalgae were higher than 13% in all cultures. The highest growth rate occurred in the 25% filtrate culture. Over 80% phosphate was removed under the 25% and 50% filtrate cultures within six days, while over 90% ammonia nitrogen was removed within five days under both conditions. The lipid content was the highest (18.1%) under the 50% filtrate condition. C16:0, C18:2n6, and C18:3n3 were dominant fatty acids. In conclusion, S. quadricauda is a viable candidate for wastewater treatment and lipid production.

Neural stem cells harvested from live brains by antibody-conjugated magnetic nanoparticles.

It stems from the magnetism: The extraction of stem/progenitor cells from the brain of live animals is possible using antibodies conjugated to magnetic nanoparticles (Ab-MNPs). The Ab-MNPs are introduced to a rat's brain with a superfine micro-syringe. The stem cells attach to the Ab-MNPs and are magnetically isolated and removed. They can develop into neurospheres and differentiate into different types of cells outside the subject body. The rat remains alive and healthy.

5-HT excites globus pallidus neurons by multiple receptor mechanisms.

Anatomical and neurochemical studies indicated that the globus pallidus receives serotonergic innervation from raphe nuclei but the membrane effects of 5-HT on globus pallidus neurons are not entirely clear. We address this question by applying whole-cell patch-clamp recordings on globus pallidus neurons in immature rat brain slices. Under current-clamp recording, 5-HT depolarized globus pallidus neurons and increased their firing rate, an action blocked by both 5-HT(4) and 5-HT(7) receptor antagonists and attributable to an increase in cation conductance(s). Further experiments indicated that 5-HT enhanced the hyperpolarization-activated inward conductance which is blocked by 5-HT(7) receptor antagonist. To determine if 5-HT exerts any presynaptic effects on GABAergic and glutamatergic inputs, the actions of 5-HT on synaptic currents were studied. At 10 microM, 5-HT increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) but had no effect on both the frequency and amplitude of miniature inhibitory postsynaptic currents (mIPSCs). However, 5-HT at a higher concentration (50 microM) decreased the frequency but not the amplitude of the mIPSCs, indicating an inhibition of GABA release from the presynaptic terminals. This effect was sensitive to 5-HT(1B) receptor antagonist. In addition to the presynaptic effects on GABAergic neurotransmission, 5-HT at 50 microM had no consistent effects on glutamatergic neurotransmission, significantly increased the frequency of miniature excitatory postsynaptic currents (mEPSCs) in 4 of 11 neurons and decreased the frequency of mEPSCs in 3 of 11 neurons. In conclusion, we found that 5-HT could modulate the excitability of globus pallidus neurons by both pre- and post-synaptic mechanisms. In view of the extensive innervation by globus pallidus neurons on other basal ganglia nuclei, this action of 5-HT originated from the raphe may have a profound effect on the operation of the entire basal ganglia network.

Electroacupuncture inhibits cyclooxygenase-2 up-regulation in rat spinal cord after spinal nerve ligation.

Electroacupuncture (EA) has long been used to treat pain including neuropathic pain, but its mechanisms remain to be delineated. Since cyclooxygenase-2 (COX-2) has been reported to increase in the spinal dorsal horn following spinal nerve ligation (SNL) and it may play a role in the neuropathic pain, we hereby tested the hypothesis that EA may affect COX-2 expression and hence neuropathic nociception after SNL. The results showed that EA (2 Hz) can significantly reduce mechanical and thermal hypersensitivity following lumbar L5 SNL in rats. Immunostaining demonstrated suppression of COX-2 expression in the spinal L4-L6 dorsal horn after EA. The present results suggest that EA may alleviate neuropathic hypersensitivity by, at least partially, inhibiting COX-2 expression in the spinal cord.

Angiomodulatory and neurological effects of ginsenosides.

Panax ginseng C.A. Meyer, one of the most popular and valued herbs, has been used extensively in traditional Chinese medicine for thousands of years. More than thirty ginsenosides, the pharmacologically active ingredients in ginseng, have been identified with various sugar moieties attached at the C-3, C-6 and C-20 positions of the steroidal skeleton. We herein review the current literature on the pharmacological effects of ginsenosides on the modulation of angiogenesis, dysregulations of which contribute towards many pathological conditions. Regarding the adaptogenic property of ginseng, the effects of ginsenosides on central nervous system are also discussed. Recent researches have pointed to the steroid hormone receptors as the target molecules to elicit the diverse cellular and physiological activities of ginseng. We believe that understanding the interaction between ginsenosides and various steroid hormone receptors may provide clues to unravel the secret of ginseng.

Neuroprotective effects of ginsenoside-Rg1 in primary nigral neurons against rotenone toxicity.

Ginsenoside-Rg1, the pharmacologically active component isolated from ginseng, demonstrated neuroprotective effects on primary cultured rat nigral neurons against rotenone toxicity. Rotenone, a common household pesticide known for its specific and irreversible mitochondria complex I inhibition, has been suggested to be the causal agent of Parkinson's disease (PD) by inducing degeneration of cells in the substantial nigra. The present study demonstrated that co-treatment of rotenone and Rg1 could reduce rotenone-induced cell death by 58% (SEM=+/-5.60; N=3). Rotenone-induced mitochondria membrane potential (MMP, DeltaPsim) depletion was restored and elevated by at least 38% (SEM=+/-2.15; N=3) by Rg1. In addition, Rg1 prevented cytochrome c release from the mitochrondrial membrane and increased the phosphorylation inhibition of the pro-apoptotic protein Bad through activation of the PI3K/Akt pathway. The protective effects of Rg1 was blocked by glucocorticoid receptor antagonist RU486, indicating that the action of Rg1 is mediated through glucocorticoid receptor (GR). In conclusion, Rg1 inhibits the mitochondrial apoptotic pathway and increases the survival chance of the primary cultured nigral neurons against rotenone toxicity. Thus, Rg1 and its related compounds may be developed as protective agents against neurodegenerative diseases induced by mitochondrial toxins.

Maximization of cell growth and lipid production of freshwater microalga Chlorella vulgaris by enrichment technique for biodiesel production.

Chlorella vulgaris was cultivated under limitation and starvation and under controlled conditions using different concentrations of nitrate (NaNO3) and phosphate (K2HPO4 and KH2PO4) chemicals in modified Bold basal medium (BBM). The biomass and lipid production responses to different media were examined in terms of optical density, cell density, dry biomass, and lipid productivity. In the 12-day batch culture period, the highest biomass productivity obtained was 72.083 mg L-1 day-1 under BBM - NcontrolPlimited condition. The highest lipid content, lipid concentration, and lipid productivity obtained were 53.202 %, 287.291 mg/L, and 23.449 mg L-1 day-1 under BBM - NControlPDeprivation condition, respectively. Nitrogen had a major effect in the biomass concentration of C. vulgaris, while no significant effect was found for phosphorus. Nitrogen and phosphorus starvation was found to be the strategy affecting the lipid accumulation and affected the lipid composition of C. vulgaris cultures.

Combined effects of land reclamation, channel dredging upon the bioavailable concentration of polycyclic aromatic hydrocarbons (PAHs) in Victoria Harbour sediment, Hong Kong.

The up-to-date concentration of polycyclic aromatic hydrocarbons (PAHs) in sediment materials of Victoria Harbour was investigated so as to evaluate the pollution potential associated with the reclamation projects in Hong Kong. A total of 100 sediment samples were collected at 20 locations. Except the control point in reservoir, the PAHs concentrations were detectable levels all sites (131-628.3ng/g, dw) and such values were higher than Dutch Target and Intervention Values (the New Dutch standard in 2016). The PAHs concentration indicating that construction waste and wastewater discharges were the main pollutant sources. Results of correlation in single cell gel electrophoresis assay (comet assay) studies also revealed that the PAHs concentration was highly correlated (<0.01) with DNA migration (i.e. the length of tail moment of fish cells) in 5mg/ml of PAHs. The above observation indicates that the PAHs present in the sediment may substantially effect the marine ecosystem. Although the dredged sediment can be a useful sea-filling material for land reclamation; however, the continuing leaching of PAHs and its impact on the aquatic environment need to be studied further.

Enhancement of Chlorella vulgaris harvesting via the electro-coagulation-flotation (ECF) method.

This article explores the potential of using an electro-coagulation-flotation (ECF) harvester to allow flotation of microalgae cells for surface harvesting. A response surface methodology (RSM) model was used to optimize ECF harvesting by adjusting electrode plate material, electrode plate number, charge of the electrodes, electrolyte concentration, and pH value of the culture solution. The result revealed that three aluminum electrode plates (one anode and two cathodes), brine solution (8 g/L), and acidity (pH = 4) of culture solution (optimized ECF harvester) The highest flocculant concentration was measured at 2966 mg/L after 60 min and showed a 79.8 % increase of flocculation concentration. Such results can provide a basis for designing a large-scale microalgae harvester for commercial use in the future.

Monitoring and assessment of heavy metal contamination in a constructed wetland in Shaoguan (Guangdong Province, China): bioaccumulation of Pb, Zn, Cu and Cd in aquatic and terrestrial components.

The objective of this study is to evaluate the current status of heavy metal concentrations in constructed wetland, Shaoguan (Guangdong, China). Sediments, three wetland plants (Typha latifolia, Phragmites australis, and Cyperus malaccensis), and six freshwater fish species [Carassius auratus (Goldfish), Cirrhinus molitorella (Mud carp), Ctenopharyngodon idellus (Grass carp), Cyprinus carpio (Wild common carp), Nicholsicypris normalis (Mandarin fish), Sarcocheilichthys kiangsiensis (Minnows)] in a constructed wetland in Shaoguan were collected and analyzed for their heavy metal compositions. Levels of Pb, Zn, Cu, and Cd in sediments exceeded approximately 532, 285, 11, and 66 times of the Dutch Intervention value. From the current study, the concentrations of Pb and Zn in three plants were generally high, especially in root tissues. For fish, concentrations of all studied metals in whole body of N. mormalis were the highest among all the fishes investigated (Pb 113.4 mg/kg, dw; Zn 183.1 mg/kg, dw; Cu 19.41 mg/kg, dw; 0.846 mg/kg, dw). Heavy metal accumulation in different ecological compartments was analyzed by principle component analysis (PCA), and there is one majority of grouped heavy metals concentration as similar in composition of ecological compartment, with the Cd concentration quite dissimilar. In relation to future prospect, phytoremediation technology for enhanced heavy metal accumulation by constructed wetland is still in early stage and needs more attention in gene manipulation area.

Neurotensin selectively facilitates glutamatergic transmission in globus pallidus.

The tridecapeptide neurotensin has been demonstrated to modulate neurotransmission in a number of brain regions. There is evidence that neurotensin receptors exist in globus pallidus presynaptically and postsynaptically. Whole-cell patch-clamp recordings were used to investigate the modulatory effects of neurotensin on glutamate and GABA transmission in this basal ganglia nucleus in rats. Neurotensin at 1 microM significantly increased the frequency of glutamate receptor-mediated miniature excitatory postsynaptic currents. In contrast, neurotensin had no effect on GABA(A) receptor-mediated miniature inhibitory postsynaptic currents. The presynaptic facilitation of neurotensin on glutamatergic transmission could be mimicked by the C-terminal fragment, neurotensin (8-13), but not by the N-terminal fragment, neurotensin (1-8). The selective neurotensin type-1 receptor antagonist, SR48692 {2-[(1-(7-chloro-4-quinolinyl)-5-2(2,6-dimethoxyphenyl)pyrazol-3-yl)carbonylamino]-tricyclo(3.3.1.1.(3.7))-decan-2-carboxylic acid}, blocked this facilitatory effect of neurotensin, and which itself had no effect on miniature excitatory postsynaptic currents. The specific phospholipase C inhibitor, U73122 {1-[6-[[17beta-3-methoyyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione}, significantly inhibit neurotensin-induced facilitation on glutamate release. Taken together with the reported postsynaptic depolarization of neurotensin in globus pallidus, it is suggested that neurotensin excites the globus pallidus neurons by multiple mechanisms which may provide a rationale for further investigations into its involvement in motor disorders originating from the basal ganglia.

Individual and combined effects of methamphetamine and ketamine on conditioned place preference and NR1 receptor phosphorylation in rats.

Methamphetamine (MA), a commonly abused psychostimulant, induces the drug dependence by enhancing the dopamine-mediated neurotransmission. Ketamine (KET) is a non-competitive N-methyl-D-aspartate receptor antagonist, which can be actually mixed with MA for polydrug abuse. In the present study, the individual and combined effects of KET (10 mg/kg, i.p.) and MA (1 mg/kg, i.p.) on conditioned place preference in rats were investigated. The alterations of serine 897 phosphorylations of NR1 receptors in the striatum and ventral tegmental area of after-conditioning rats were measured immunochemically. The results showed repeated administrations of MA, KET and their combination, at the doses studied, all could induce psychological dependences evaluated by conditioned place preference. KET was not able to suppress the MA-induced place preference. The modulations of NR1 phosphorylations in basal ganglia were partly responsible to place preference. Although the alterations induced by KET were not significant in most areas we studied, MA showed a significant increase in the ventral tegmental area but a marked decrease in caudate putamen and nucleus accumbens. Such alterations were much more significant when KET and MA were combined. These results have important implications for public awareness of harm with combined drug abuse. Further investigations toward the specific interaction of the two drugs are necessary.

Differential expression of NMDA and AMPA/KA receptor subunits in the inferior olive of postnatal rats.

We have employed immunohistochemistry to determine the expression patterns of receptor subunits of N-methyl-d-aspartate (NMDA-NR1 and NR2A/B) and alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid/kainic acid (AMPA/KA-GluR1, GluR2, GluR2/3, GluR4, and GluR5/6/7) in the inferior olive of postnatal rats up to adulthood. Immunoreactivity for distinct receptor subunits was predominantly localized in the soma and dendrites of neurons. Semi-quantification showed that the overall immunoreactivity in the inferior olive of adults was intense for GluR1, moderate for NR1 and NR2A/B, and low for GluR2, GluR2/3, GluR4, and GluR5/6/7. At P7, GluR1 was restricted to the dorsomedial cell column, subnucleus beta, principal nucleus and ventrolateral protrusion while the other subunits were found in all subnuclei of the inferior olive. The immunoreactivities for all glutamate receptor subunits ranged from low to moderate. As the rats matured, the immunoreactivity of GluR4 decreased after the second postnatal week, while those of the other subunits showed a general trend of increase, reaching adult level during the third postnatal week. Double immunofluorescence revealed that all NR1-containing neurons exhibited NR2A/B immunoreactivity, indicating that native NMDA receptors comprise of hetero-oligomeric combinations of NR1 and NR2A/B. Furthermore, co-localization of NMDA and AMPA/KA receptor subunits was demonstrated in individual neurons of the inferior olive. All NR1-containing neurons exhibited GluR1 immunoreactivity, and all NR2A/B-containing neurons showed GluR5/6/7 immunoreactivity. Our data suggest that NMDA and AMPA/KA receptors are involved in glutamate-mediated neurotransmission, contributing to synaptic plasticity and reorganization of circuitry in the inferior olive during postnatal development.

Comparative assessment of water quality parameters of mariculture for fish production in Hong Kong Waters.

The objective of the study is to evaluate the effect of fish cultivation on water quality in fish culture zone (FCZ) and analysed by Principle Component Analysis (PCA). 120 surface water samples were collected from Hong Kong Waters (60 samples in Victoria Harbour and another 60 in Ma Wan FCZ). Significant difference was found in dissolved oxygen (MW: 59.6%; VH: 81.3%), and Escherichia coli (MW: 465 CFU/100 ml; VH: 162.5 CFU/100 ml). Three principle components are responsible for water quality variations in the studying sites. The first component included E. coli (0.625) and dissolved oxygen (0.701). The second included E. coli (0.387) and ammonical-nitrogen (0.571). The third included E. coli (0.194) and ammonical-nitrogen (0.287). This framework provides information to assess the relative contribution of eco-aquaculture to nutrient loads and the subsequent risk of eutrophication. To conclude, a rigorous monitoring of water quality is necessary to assess point and nonpoint source pollution. Besides, appropriate remediation techniques should be used to combat water pollution and achieve sustainability.

Differential expression of GABA(B)R1 and GABA(B)R2 receptor immunoreactivity in neurochemically identified neurons of the rat neostriatum.

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the neostriatum. Functions of GABA are known to mediate GABA(A) and GABA(B) receptors. A functional GABA(B) receptor is known to compose of heteromeric subunits, namely the GABA(B)R1 and GABA(B)R2 subunits. Our previous report (Yung et al. [1999] Brain Res. 830:345-352) has demonstrated that all major subpopulations of striatal neurons express GABA(B)R1 immunoreactivity. The cellular localization of the second subunit of GABA(B) receptor protein, i.e., GABA(B)R2 immunoreactivity, in the rat neostriatum is not yet known. By using a new commercially available specific antibody against GABA(B)R2, immunofluorescence was performed to investigate the cellular expression of GABA(B)R2 in neurochemically identified subpopulations of neurons in the rat neostriatum. Immunoreactivity for GABA(B)R2 was primarily found in the neuropil of the rat neostriatum. Double labeling revealed that those perikarya that expressed immunoreactivity for parvalbumin, choline acetyltransferase, nitric oxide synthase, glutamate receptor two, N-methyl-D-aspartate receptor one, or GABA(A)alpha1 receptor, respectively, did not express GABA(B)R2 immunoreactivity. In addition, perikarya and most of the neuropilar elements in the neostriatum that expressed glutamic acid decarboxylase 67 immunoreactivity were found to be GABA(B)R2-negative. In contrast, immunoreactivity for GABA(B)R1 was found to be expressed by all of the above neuronal subpopulations. Moreover, a vast number of SV2-immunoreactive profiles and a number of tyrosine hydroxylase-immunoreactive profiles in the neuropil of the neostriatum were found to display GABA(B)R2 immunoreactivity. The present results indicate that there is a differential expression of GABA(B)R2 and GABA(B)R1 immunoreactivity in different subpopulations of striatal neurons that are identified by their specific neurochemical markers. Immunoreactivity for GABA(B)R2 is likely to localize in neuropilar elements of the neostriatum that may belong to non-GABAergic elements. These findings provide anatomical evidence of GABA(B)R2 receptor localization in the neostriatum that may have an important functional implication of the GABA(B)-mediated functions in neurons of the neostriatum.

Neurokinin peptides and neurokinin receptors as potential therapeutic intervention targets of basal ganglia in the prevention and treatment of Parkinson's disease.

Parkinson's disease (PD) is a serious motor disorder and it is the second most common brain degenerative disease in human. PD is known to be caused by degeneration of dopamine neurons in the substantia nigra but the cause of cell death is largely unknown. Mammalian neurokinins [NKs] are a group of neuropeptides that include substance P (SP; neurokinin-1, NK-1), substance K (SK; NK-2; neurokinin A), and neuromedin K (NK; NK-3; neurokinin B). Their biological effects as neurotransmitters, neuromodulators, or neurotrophic-like factors are mediated by three distinct neurokinin receptors, namely SP receptor (SPR: NK-1 receptor, NK-1R), SKR (NK-2R), and NKR (NK-3R). Several lines of evidence have indicated that neurokinins are implicated in the pathogenesis of PD. First, decreases of SP level and SP-immunoreactivity have been found in nigral and striatal tissues of animals with PD and postmortem PD patients. Second, NKs exert neuroprotective effects on neurons. In addition, NK receptors, namely NK-1 and NK-3 receptors, are abundantly localized in dopaminergic and cholinergic neurons of the basal ganglia, indicating that these neurons are under the physiological regulation of NKs. Moreover, modulation in motor activity occurred in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, PD animal model, after systemic administration of NK receptor agonists. NKs and NK receptors, therefore, might be important molecules that are associated with functions and survival of neurons in the basal ganglia, in particular the dopamine neurons. Further studies should be devoted to elucidate the functional roles of NK systems in (a) the neuropathogenesis and neuroprotection during the course of PD, (b) the efficacy of NK receptor drugs towards PD, and (c) potential therapeutic intervention that targets at the prevention or treatment of PD.

Distinct cellular distribution of GABA(B)R1 and GABA(A)alpha1 receptor immunoreactivity in the rat substantia nigra.

GABA is one of the most important inhibitory neurotransmitters in the substantia nigra. Functions of GABA are mediated by two major types of GABA receptors, namely the GABA(A) and GABA(B) receptors. Subunits of both the GABA(A) and GABA(B) receptors have been cloned and functional characteristics of the receptors depend on their subunit compositions. In order to characterize the cellular localization of GABA(B)R1 and GABA(A)alpha1 subunit immunoreactivity in subpopulations of neurons in the rat substantia nigra, double and triple immunofluorescence was employed. Over 90% of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra pars compacta were found to display immunoreactivity for GABA(B)R1. In contrast, immunoreactivity for GABA(A)alpha1 was found to be primarily displayed by neurons in the substantia nigra pars reticulata. Around 85% of the GABA(A)alpha1-immunoreactive reticulata neurons were found to display parvalbumin immunoreactivity and some GABA(A)alpha1-positive reticulata neurons were found to be parvalbumin negative. In addition, triple-labeling experiments revealed that at the single cell level, the tyrosine hydroxylase-positive, i.e. the dopaminergic neurons in the compacta displayed intense immunoreactivity for GABA(B)R1 but not GABA(A)alpha1 receptors. The parvalbumin-positive neurons in the reticulata displayed intense immunoreactivity for GABA(A)alpha1 but not GABA(B)R1 receptors. The present results demonstrate in the same sections that there is a distinct pattern of localization of GABA(B)R1 and GABA(A)alpha1 receptor immunoreactivity in different subpopulations of the rat substantia nigra and provide anatomical evidence for GABA neurotransmission in the subpopulations of nigral neurons.

Depletion of glutamate GluR2 receptor-containing neurons in the rat neostriatum by specific immunotoxin.

In the present study, a novel GluR2 receptor-specific immunotoxin was produced. The immunotoxin was produced by conjugation of molecules of trichosanthin, a ribosome inactivating protein, with goat anti-mouse immunoglobulin molecules. The secondary antibody was then combined with a commercially available GluR2 specific primary antibody to form an immunotoxin. The immunotoxins were unilaterally injected either into the neostriatum or into the lateral ventricle of rats. After one week, ipsilateral turning movements were observed after apomorphine treatments in those animals injected by the striatal route. In perfuse-fixed sections of the neostriatum, immunoreactivity for GluR2 was found to decrease in the striatal-lesioned animals. Most of the GluR2-immunoreactive perikarya in the neostriatum, the presumed medium spiny neurons, were depleted. In addition, immunoreactivity for GluR2/3, GluR5/6/7 and NMDAR1 was found to decrease to a different extent in the lesioned neostriatum. The number of GluR1-immunoreactive perikarya in the neostriatum, a group of striatal interneurons, was not affected by the GluR2 lesion. Ventricular administration of the GluR2 immunotoxin however, was found to be less potent. These results demonstrate for the first time that an indirect immunotoxin is useful for immunolesioning. A difference in potency was also observed in different routes of administration. The depletion of GluR2-containing medium spiny neurons in the neostriatum may upset the balance of the output systems of the basal ganglia and has a profound effect in movement control of the animals.