Optimization of hydrolysis conditions of amino acid analysis for UHPLC-UV antigens content determination: Bexsero vaccine a case study.

In the present study the compositional analysis of the amino acids released by the acidic hydrolysis of the vaccine antigens was approached as an alternative to the dye-binding methods, for improvement of the quality control. In particular, the Analytical Quality by Design principles were undertaken in optimizing the hydrolysis conditions of the antigens to be applied prior to the quantitation by UHPLC-UV. Bexsero was used as a case study; it is a recombinant meningococcal B vaccine and one of its critical quality attributes is the content of the three core protein antigens, namely Neisseria Heparin Binding Antigen, factor H binding protein and Neisseria adhesin A, in the final formulation.

Acquisition of an appetitive behavior prevents development of stress-induced neurochemical modifications in rat nucleus accumbens.

In rats, exposure to chronic unavoidable stress produces a decrease in dopamine output in the nucleus accumbens shell that is accompanied by a decreased density of the dopamine transporter and an increased activity of the dopamine-D(1) receptor complex. These modifications have been hypothesized to be adaptive to decreased dopamine output in stressed rats. We investigated whether the learning of an appetitive behavior sustained by palatable food, which is associated with increased dopamine output in the nucleus accumbens shell as measured by microdialysis experiments, would affect the modifications induced by chronic stress exposure on dopamine transporter density and dopamine-D(1) receptor complex activity in the nucleus accumbens.

The efficacy of reboxetine in preventing and reverting a condition of escape deficit in rats.

Background: Different stress-induced experimental models of depression are currently used to study the efficacy and mechanism of action of classical or potential antidepressant compounds. We studied the effect of single and repeated administrations of reboxetine, an antidepressant that selectively inhibits noradrenaline reuptake, in the prevention and reversal of stress-induced escape deficit. Moreover, we examined the effect of chronic reboxetine on the stress-induced decrease of dopamine output in the nucleus accumbens shell (NAcS).

Sardinian alcohol-preferring and non-preferring rats show different reactivity to aversive stimuli and a similar response to a natural reward.

Sardinian alcohol-preferring (sP) and non-preferring (sNP) rats were studied to ascertain whether some behavioral and/or neurochemical traits, beyond ethanol preference, differentiated the two lines. Spontaneous reactivity of Wistar, sP and sNP rats to aversive or pleasurable stimuli was examined in an avoidance test, an elevated plus maze test, and in response to palatable food presentation. As the mesocorticolimbic dopaminergic system plays a relevant role in the response to rewarding or aversive stimuli, extraneuronal dopamine levels and cocaine-induced dopamine accumulation in the nucleus accumbens shell (NAcS) and medial prefrontal cortex (mPFC) were studied by microdialysis in the three groups of rats.

Effects of long-term acetyl-L-carnitine administration in rats--II: Protection against the disrupting effect of stress on the acquisition of appetitive behavior.

Long-term acetyl-L-carnitine (ALCAR) administration prevents the development of escape deficit produced by acute exposure to unavoidable stress. However, it does not revert the escape deficit sustained by chronic stress exposure. Rats exposed to chronic stress show a low dopamine (DA) output in the nucleus accumbens shell (NAcS) and do not acquire an appetitive behavior sustained by the earning of vanilla sugar (VS) made contingent on the choice of one of the two divergent arms of a Y-maze (VS-sustained appetitive behavior, VAB), while control rats consistently do.

Selective modifications in the nucleus accumbens of dopamine synaptic transmission in rats exposed to chronic stress.

Stressful events are accompanied by modifications in dopaminergic transmission in distinct brain regions. As the activity of the neuronal dopamine (DA) transporter (DAT) is considered to be a critical mechanism for determining the extent of DA receptor activation, we investigated whether a 3-week exposure to unavoidable stress, which produces a reduction in DA output in the nucleus accumbens shell (NAcS) and medial prefrontal cortex (mPFC), would affect DAT density and DA D1 receptor complex activity in the NAcS, mPFC and caudate-putamen (CPu). Rats exposed to unavoidable stress showed a decreased DA output in the NAcS accompanied by a decrease in the number of DAT binding sites, and an increase in the number of DA D1 binding sites and Vmax of SKF 38393-stimulated adenylyl cyclase.

Effects of the essential oil from citrus lemon in male and female rats exposed to a persistent painful stimulation.

The ability of olfaction to modulate behavior in mammalian species has repeatedly been demonstrated. Here we tested the properties of the volatile components of lemon essential oil. Male and female rats were allowed to inhale the aroma while experiencing a persistent nociceptive input (50 microl formalin, 5%); in the same animals the c-Fos immunohistochemistry was used to test the degree of neuronal activation of areas belonging to the limbic system.

Effects of long-term acetyl-L-carnitine administration in rats: I. increased dopamine output in mesocorticolimbic areas and protection toward acute stress exposure.

Acetyl-L-carnitine (ALCAR) is the acetyl ester of carnitine that has been reported to be beneficial in depressive disorders and Alzheimer's disease. A 7-day administration of ALCAR in rats increased dopamine and serotonin output in the nucleus accumbens shell and it prevented the development of escape deficit produced by acute exposure to unavoidable stress. No tolerance developed to this protective effect, which appeared to be mediated by (1) the activation of 5-HT(1A) receptors, as it was antagonized by the administration of WAY100635 30 min before stress exposure; and (2) a process of neuronal plasticity dependent on NMDA receptor activity, as subcutaneous dizocilpine infusion during ALCAR treatment prevented the development of the protective effect on stress.

Sex differences in the citrus lemon essential oil-induced increase of hippocampal acetylcholine release in rats exposed to a persistent painful stimulation.

The microdialysis technique was used to study the ability of essential oil from citrus lemon to modulate hippocampal acetylcholine (ACh) release in male and female rats. Animals were allowed to inhale this odor while experiencing a persistent nociceptive input (50 microl formalin, 5%) or under control conditions (sham-injection). In males, exposure to the essential oil did not change the time course and magnitude of the ACh increase induced by pain.